The results show that the CdCl2 treatment did not promote significant microstructural changes in HT-CdTe films, which grow with large and randomly oriented The absorber layer is made from direct band gap CdTe TFs. Binary and ternary transparent oxides of Cd, In, Zn, and Sn have been prepared by sputtering and chemical vapor deposition, and their structural and electro-optical properties have been investigated. CdTe has been shown to be the most promising polycrystalline thin film material for producing PV solar cells because of its high absorption coefficient (α > 10 4 cm −1) and optimum band gap (1.5 eV). Die oplossing lê egter in die gebruik van dunlagieselle waar die materiaalkoste baie laag is en waar opskaling en massaproduksie ekonomies kompeterend gedoen kan word. The mechanism is electrostatic, and hence independent of the geometry of the boundary, thereby explaining the universally high collection efficiency of Cl-doped CdTe solar cells. These cells were exposed to an accelerated stress test. firstname.lastname@example.org, 303-384-6451 Presented at the China New Energy International Forum and Fair 2010. Room-temperature barrier heights exceeding 0.5 eV will generally result in significant fill-factor reduction. Impedance analysis showed the improved cadmium chloride treatment—resulting from the additional etching step—removed the grain boundary component from the equivalent circuit, indicating a grain boundary passivation effect. They are among the lowest-cost types of solar cell, although a comparison of total installed cost depends on installation size and many other factors, and has changed rapidly from year to year. Conference Record of the IEEE Photovoltaic Specialists Conference.  demonstrated significant discrepancy between the model predication using the five-parameter model and the actual panel measurement. CdTe Solar Cells. Analysis indicates that present modules are limited in efficiency by shunt resistance and optical absorption losses in the glass superstrate. boundaries. The microstructure of 4–13 µm thick CdTe absorber layers in CdTe/CdS/ITO/glass solar cell structures grown by metal-organic chemical vapour deposition (MOCVD) at 350 °C has been studied. Application of ZnO1−xSx as window layer in cadmium telluride solar cells, All-sputtered CdS/CdTe solar cells on polyimide, The properties and optimization of ZnTe:Cu back contacts on CdTe/CdS thin film solar cells, Doping limits in II–VI compounds — Challenges, problems and solutions, Fabrication of flexible CdTe solar modules with monolithic cell interconnection, P-Doping limit and donor compensation in CdTe polycrystalline thin film solar cells, High-efficiency flexible CdTe solar cells on polymer substrates, Bifacial configurations for CdTe solar cells, Spray deposition of CdTe–Te thin films using ethylene-diamine-tetra-acetic acid as a complexing agent in the precursor solution, Single crystalline CdTe solar cells grown by MOCVD, Characterization of etching procedure in preparation of CdTe solar cells, Strategies to Increase CdTe Solar-Cell Voltage, New window materials used as heterojunction partners on CdTe solar cells, Photovoltaic properties of ZnO/p-CdTe thin film heterojunctions, Electric and photovoltaic properties of CdTe pn homojunctions, Chemical etching of crystal and thin film cadmium telluride, Screen-printed CdS/CdTe solar cell of 12.8% efficiency for an active area of 0.78 cm2, Stable Cu-Based Back Contacts for CdTe Thin Film Photovoltaic Devices, Direct conversion of solar energy through photovoltaic cells, Screen printed thin film CdS/CdTe solar cell, Excited states of Ag and Cu acceptors in CdTe, Mass Spectrometric Study of the Phase Boundaries of the CdS-CdTe System, n- And p-type post-growth self-doping of CdTe single crystals, DLTS and admittance measurements on CdS/CdTe solar cells, Chemical and Electronic Properties of Metal/Sb2Te3/ CdTe Contacts for CdTe Thin Film Solar Cells Studied by Photoelectron Spectroscopy, Fabrication of stable large-area thin-film CdTe photovoltaic modules. Download Full PDF Package. We believe that these represent the highest efficiencies yet obtained for CdS/CdTe cells with such submicron absorber-layer thicknesses. We ascribe this to annihilation of VCd as a result of Cdi diffusion. Kristallynesilikon-sonselle domineer tans die wereldmark. What is more, the doping concentration in the vicinity of the CdTe∕CdS heterojunction increases for the formation of substitutional SbTe- acceptors under the Cd-rich conditions. Due to bowing effects, the CdTe 1−xSex alloys exhibit narrower band gaps than CdTe, enhancing the JSC in the CdTe-based solar cells for long-wavelengths. Comparisons are made between this work and previous studies of ZTO buffer layers. However, although such doping has been almost ubiquitous since the development of this processing route over 25 years ago 6 , CdCl 2 has two severe disadvantages; it is both expensive (about 30 cents per gram) and a water-soluble source of toxic cadmium ions, presenting a risk to both operators and the environment during manufacture. Bi-doped CdTe thin films where the films were air annealed at the different temperatures. The MoO3-x/Au back contact layers were deposited by thermal evaporation. In the remaining sets, the graphite layer was removed before the application of the Ag or Ni. Formation of low resistance back contacts in, CdTe thin film solar cells has been a research issue for many years. ZTO films having various Zn/Sn ratio were produced in a single deposition by co-sputtering from Zn and Sn targets in an O2 atmosphere. The CdCl2 treatment is shown to cause a reduction in the CdTe defect density at regions close to the interface and induce recrystallization of the CdS layer. Using atomic force microscopy (AFM), we have obtained images of the coverage of CdTe deposited by radio-frequency magnetron sputtering (RF sputtering) on a CdS substrate. When performed at the same conditions, the CdCl2 vapor treatment is more effective in the recrystallization and grain-growth processes than the solution CdCl2 treatment. Author links open overlay panel Deng-Bing Li Sandip S. Bista Zhaoning Song Rasha A. Awni Kamala K. Subedi Niraj Shrestha Puja Pradhan Lei Chen Ebin Bastola Corey R. Grice Adam B. Phillips Michael J. Heben Randy J. Ellingson … Photoinduced electron transfer (PET) from N‐methylaniline (NMA) to a photoexcited CdTe quantum dot (QD*) is studied in toluene. Nano Energy. Among these compounds, Cs2InCuCl6 and MA2InCuCl6 were found as, The ZnO/CdTe/CuSCN heterostructure was analyzed as a candidate to act as an inorganic eta-solar cell. Cases (I) and (II) correspond to C=17.90 and 50 mA cm−2 K3 respectively, whereas, case (III) corresponds to C.T3=A=1.5×108 mA cm−2. For CdS CBD, the extent of the desired heterogeneous reaction on the substrate surface is limited by two major factors, the competing homogeneous reaction in solution and deposition of material on the CBD reactor walls. Furthermore, the focussed ion beam technique is shown to reveal voids formed within the device's thin-film layers at various processing stages that have not been previously observed in working cell structures. For the deeper states, the broadening parameter was observed to increase, indicating fluctuations of the charge on a microscopic scale. This article describes the latest information achievement in the field of solar cells [Solar cell efficiency tables (version 48) containing the latest efficiency of different types of solar cells published on July 2016. Zn rich films (~85% Zn, ~15% Sn) were found to give higher device efficiency, η = 8.76 ± 0.43%, than Sn rich (~31% Zn, ~69% Sn) films, η = 6.76 ± 0.51%. Table 1: Overview of current status of CIS and CdTe solar cells and modules. Copper-free solar cells based on the CdS/CdTe/FeS2-NC/Au architecture exhibit device efficiencies >90% that of a standard Cu/Au back contact devices. The superstrate CdZnS/CdTe solar cells were grown side-by-side on ITO/glass and ZnO/ITO/glass substrates by MOCVD, where the CdZnS thickness was varied between 60 and 150 nm. Copyright © 2013 John Wiley & Sons, Ltd. An isothermal evaporation method by means of a Knudsen cell-mass spectrometer combination has been applied to the determination of the phase boundaries in the CdS-CdTe system in the temperature range of 650Â°--720Â°C. This is caused by the fact that the conventional device structure must be inverted, which imposes severe restrictions on device processing and consequently limits the electronic quality of the CdTe layer. We further report that the use of combined CdS/CdSe window layers can realize high open circuit voltages and maintain the JSC enhancements. Preliminary results from CdTe/CdS thin film photovoltaic devices demonstrate a notable efficiency of 9.8%. The performance of sputtered CdS/CdTe solar cells with MoO3−x/Au contacts was examined. Yet, the problems of barrier formation at the back contact as well as the formation of a p–n junction with reduced recombination losses have to be solved. Some have attacked the CdTe PV technology as unavoidably polluting the environment, and made comparisons of hypothetical emissions from PV modules to cadmium emissions from coal-fired … It is concluded that Cd‐vacancy generation is the main mechanism of type conversion. The existence of this inhomogeneous conductive layer directly affects the current transport and is probably the reason for needing thick CdTe in these devices. The role of CdCl2 in prompting recrystallization, grain growth and interdiffusion between CdS and CdTe layers in physical vapor-deposited CdS/CdTe thin-film solar cells is presented. In this work CdTe solar cells in substrate configuration were grown with evaporated MoOx back contact buffer layers and efficiencies of up to 10% could be achieved without using Cu in the back contact processing. As the p–n junction can be deposited by MOCVD, the in situ CdCl2 treatment of the device allows for containment of the whole process. These changes are quantitatively described by microtexture analysis, a spatial distribution of the orientation Band alignment does not indicate the formation of a good back contact. Grain diameter is shown to increase in the pressure range 2–200 Torr, following the linear relationship D (μm)=0.027×P (Torr)+0.90. Such changes can be attributed to the grain-boundary strain and the modification of the charge trapped at the grain-boundary interface states in polycrystalline Materials for Renewable and Sustainable Energy. Acostac, R. Guardiand, J.A. The CdTe film was deposited onto the interlayer by close spaced sublimation. Cadmium telluride, CdTe, is now firmly established as the basis for the market-leading thin-film solar-cell technology. In addition, SCI is expanding its proactive safety, health, environmental, and disposal program dealing with issues surrounding cadmium. The spectrally selective materials are thin films based on metals (normally gold or titanium nitride) or wide band gap semiconductors with heavy doping (normally based on indium, tin, or zinc). Stern‐Volmer analysis is well complemented by stochastic kinetic analysis. The difference between cells which received a CdCl2 treatment in air and those which received the treatment in vacuum is discussed. Applied Physics Letters, 2014. These devices exhibited a 10–15% decrease in efficiency primarily due to fill factor loss during stress. We found that neither Cu loss in the back contact nor Cu accumulation in the CdS layer, which are often associated with degradation of CdTe solar cells, occurred in our case. This is lower than in GaAs solar cells, even though GaAs has a smaller bandgap; this is because it is more difficult to achieve simultaneously high hole density and lifetime in II–VI materials than in III–V materials. Lead-free double perovskites Cs 2 InCuCl 6 and (CH 3 NH 3 ) 2 InCuCl 6 : electronic, optical, and el... ZnO/CdTe/CuSCN, a promising heterostructure to act as inorganic -solar cell, Development of a substrate configuration CdTe/CdS solar cell on flexible molybdenum substrate. During processing of CdTe solar cells, sodium can diffuse from the glass substrate into the active layers and can considerably affect CdTe solar cell properties. Cha! Cl substitutes for a large proportion of the Te atoms within a few unit cells of the grain boundaries. The maximum achievable Voc, Jsc, FF and η of solar cells are calculated for AM1.5G and AM0 spectra and are compared with theoretical and experimental results in the literature. Development of island size, density and coverage demonstrates that growth proceeds via the process of island nucleation, island growth and density increase, followed by coalescence, channel formation and secondary nucleation. Fotovoltaïese elektrisiteit (PV) is ’n gratis en skoon bron van hernubare energie wat oplossing bied vir baie sosio-ekonomiese probleme van beide Eerstewêreld- en Derdewêreldgemeenskappe. In this work the impact of Zn1-xSnxO (ZTO) buffer layers on device performance are examined. ndeza, U. Palb, C. Magan˜ac, D.R. A systematic investigation of the CE design revealed the high electrocatalytic activity of GOR due to the presence of organic functional groups, graphitic edge sites and a quasi-one-dimensional (quasi-1D) structure, which increases the interfacial charge transfer kinetics from the CE to the polysulfide electrolyte. (d)–(g) Statistical results for MZO/CdTe solar cell performances with different CuCl annealing temperatures and CuCl solution volumes in RTA treatment. C-V measurements revealed a decrease in net acceptor concentration by 70% and SCAPS simulations confirmed that this decrease can fully explain the observed performance losses of the solar cells. Despite the challenges faced by flexible structures, efficiencies of up to 13.8% and 7.8% have been achieved in superstrate and substrate cell, respectively. Microwave Synthesized CuxS and Graphene Oxide Nanoribbon Composite as Highly Efficient Counter Elect... Synergistic photovoltaic-thermoelectric effect in a nanostructured CdTe/Bi2Te3 heterojunction for hy... Growth and characterization of CdTe absorbers on GaAs by MBE for high concentration PV solar cells, Thin films of CdTe produced using stacked elemental layer processing for use in CdTe/CdS solar cells, Novel approach to the chemical bath deposition of chalcogenide semiconductors, Preparation of Cu2Te Thin Films and Back-Contact Formation of CdTe Solar Cells. Temperature dependent JV measurement showed the use of P3HT reduced the barrier to (0.29–0.33eV) from the value achievable with Au (0.39–0.42eV), but inclusion of Cu into either of the structures gave the lowest barriers (0.21–0.22eV). When the thickness of the ITO window layer is 325 nm, V oc = 0.82 V, J sc = 17 mA/cm2, and FF = 57.4%, the highest power conversion efficiency (PCE) is 8.6%. The larger grains had ≪111≫ orientation, whereas the smaller grains were randomly oriented, which provided insight on the grain-growth mechanism after recrystallization. Annealing in both ambients promoted grain growth (with Rayleigh grain size distribution functions and Burke–Turnbull exponents being n = 7 at 440 °C and ~4 at 400 °C), a development of the grown-in preferred orientation from [1 1 1] to [2 1 1], and relief of the grown-in compressive stress. We find that after this process, a thin layer of CdxHg1−xTe forms between the CdTe and Te-rich layers, giving a structure of CdTe/CdxHg1−xTe/Te. However, when Cu was included the peak performance of devices having P3HT/Cu/Au and Cu/Au contacts were comparable at 14.7% respectively but the P3HT/Cu/Au contact displayed a significantly higher average performance through increased uniformity of the device response. Several resistive oxides have been found to be effective buffer layers. Efficient electroplated CdS/CdTe solar cells can be fabricated by heat treating and type‐converting the n‐CdTe films deposited on CdS layers. The intrinsic charge carrier mobilities for Cs2InCuCl6 along the L-Г path are predicted to be comparable to those for MAPbI3. This novel cell is capable of converting light and heat into electricity via combined photovoltaic and thermoelectric processes, providing a simple and elegant material structure for development of high efficiency solar cells which can harvest solar energy over a wider solar spectrum. Band measurements using photoelectron spectroscopy and synchrotron techniques correlate band alignment measurements with efficiency parameters in the design of HRT and CdS layers. Application of the nucleation model to influence the growth of solar cell quality CdTe layers is demonstrated by the use of elevated gas pressures to increase grain size. Preliminary results on the effects of in situ CdCl2 treatment on MOCVD CdS/CdTe:As devices are reported and compared with untreated devices, using current–voltage characterisation. The vacuum deposited Sb 2Te3 layers do not react with the CdTe substrate. Post-synthesis annealing of the layers using CuCl2/CdCl2/methanol was also investigated. Cadmium telluride (CdTe) photovoltaics or also called Cadmium telluride solar cell is a kind of photovoltaic (PV) technology that can produce electricity from sunlight using a thin-film of compound cadmium telluride to absorb and convert sunlight into electricity. The nucleation process shows a temperature-dependent incubation time. For the optimal treatment conditions, there was complete recrystallization and grain growth, and further decrease in stress. Timothy A. Gessert. Advanced. HwTgiFaFa la3bgR g Fluorine doped tin oxide (FTO) coated glass (TEC 12; Pilkington NA) is used as the substrate for fabricating CdTe solar cells. Blessed with a direct 1.5 eV bandgap, good optical … Two of these device sets were made with Ag and Ni deposited on a Cu-doped graphite layer. Highest Voc, FF and η are achieved for case (III). For CdCl2 treatments at moderate temperature/time, there was partial recrystallization, and a moderate decrease in the concentration of deep levels. The early stage growth mechanisms of sublimation-grown thin-film polycrystalline CdTe are evaluated by growth interrupts and ex-situ AFM for growth under 100 torr of inert gas. kept interest at a low level and confined to only a few laboratories. The growth of CdTe films on CdS/glass was investigated. Recommendations for processing condition optimization are made based on the results of this study. A conformal and uniform CdTe coverage of the ZnO columns was achieved, producing a very efficient light trapping effect. Their applications to energy-efficient windows are covered in detail, experimentally as well as theoretically, and briefer discussions are given applications to solar cells and solar collectors. In this work, we develop a new formalism that enables much greater insight into which factors dominate the TRPL decay dynamics. Shorter-wavelength photons will be more affected by the interface recombination and drift compared to the longer ones. However, the PET rate increases with decreasing QD size, which is commensurate with the observation that the chemical driving force (ΔG) increases with decreasing the QD particle size. A proper comparison of the two CdS/CdTe solar cells shows that the cell with the Te layer has a higher current because of the higher blue photosensitivity, but has a lower open circuit voltage in relation to the absorber band gap. The highly stable Cu1.18S-GOR CE has the added advantage of a favourable energy band alignment with the redox potential of the polysulfide electrolyte, which reduces the loss of charge carriers and thus can increase the PCE of QDSSCs. We have studied the effect of post formation annealing treatments of the CdTe/CdS junction on the opto-electronic parameters of the device and correlated the opto-electronic properties with the interdiffusion of Te and S across the CdTe/CdS interface. Simulation and performance study of Nanowire CdS/CdTe Solar Cell Submitted by Examination Roll No. Electron backscatter diffraction showed that these films had a mixture of small and large grains, many larger than 30 μm. From 25 elemental cells with 4 multiplied by 4 cm**2 substrate, a 1 watt module has tentatively been constructed with a module efficiency of 2. The nucleation rate, negligible at the beginning, reaches a maximum after a certain time and then tends to zero for a longer deposition time. D.-B. Above 470 °C the texture changed to mostly (311) and (220) orientations. This design allows CdTe solar cells to be made thinner and more efficient. Careful analysis of the Cd–Te P–T–X phase diagram, allows us to prepare conducting p- and n-type CdTe, by manipulating the native defect equilibria only, without resorting to external dopants. CdTe solar cells with a single-phase hexagonal Cu2Te layer annealed at a temperature of 180 °C show a good ohmic-contact behavior. The structures of the CdTe films were determined by XRD and a strong (111) orientation was observed within the temperature range 250 °C–470 °C. In addition, the solubility properties and relatively high thermal stability of the residue suggest the presence of the oxychloride Cd 3 Cl 2 O 2 rather than CdCl 2 as the major chlorine-containing component. The intensity and the spectrum of the PL suggest that films grown from the homemade UT target were of comparable quality to those grown from the commercial target. In both HRT systems, controlling electron affinity to optimize front contact band alignment is an important consideration. of the grains. Using Sentaurus Device Software, we analyze how bulk and interface recombination affect time-resolved photoluminescence (TRPL) decays in CdTe solar cells. There was a significant increase in the cathodoluminescence signal, indicating a decrease in the concentration of deep levels. This thesis presents various studies into the effects of both growth and processing conditions on a) the electrical properties of interfaces of the CdTe solar cell, and b) the photovoltaic (PV) performance. Wyatt Metzger. The precursors used are dimethylcadmium and tertiarybutylchloride or n-hexylchloride, respectively for the cadmium and chlorine species. A method to control the grain size of CdTe thin films deposited by close space sublimation using chamber pressure is demonstrated. A simple model is proposed to explain both the observed differences in device behavior as copper is added or removed from the contact region, and how copper movement depends on electrical bias. By subsequent deposition of metals a chemical reaction is induced forming metal-tellurides, a metal/Sb-alloy and elemental Sb. This paper . The photovoltaic performance (efficiency η) of an ITO/CdS/CdTe structure cell is studied in this article according to its electrical properties. This study was carried out using quantitative secondary ion mass spectrometry (SIMS) profiling from the CdTe surface through the glass substrate. Such annealing was found to substantially increase the grain size of the layers produced. Films have been characterised by spectroscopic methods (UV–vis, PL and XPS), microscopy (SEM and TEM) and powder XRD. The use of a buffer layer has been found to improve solar cell performance in particular when the CdS thickness is relatively small. Results are presented on the surface morphology and layer structure. The thickness of CdS was constant at 50–55 nm while the CdTe thicknesses ranged from 0.25μm–2.1 μm. The chemical phase, composition, microstructure and optical properties of such layers were studied for their possible use in CdTe solar cells. diffraction patterns from individual grains. Also, high absorption coefficient is calculated from the results, which is ∼5 x 105 cm-1 in solar radiation spectrum. Finally, we carried out calculations of the band edge positions for MA2InCuCl6 and Cs2InCuCl6 to offer guidance for solar cell heterojunction design and optimization. This solar cell has been studied in terms of stability to variation of temperature and also other properties of used materials have been investigated in the paper . CdTe solar cells with and without a highly conformal intrinsic ZnO buffer layer were studied. The limitations of each deep-level characterization technique dictated by the polycrystalline nature of the CdTe/CdS heterostructure, were taken in consideration. Density functional calculations reveal the mechanism, and further indicate the grain boundaries are inverted to n type, establishing local p-n junctions which assist electron-hole pair separation. Darius Kuciauskas. The reference list is extensive and aims at giving an easy entrance to the many varied aspects of TCs. When the CdTe absorber layer is thin (<1 μm), it is impossible to avoid a noticeable decrease of the short-circuit current density. For long-term stability study, all devices were subjected to elevated temperature (100 °C), open-circuit voltage bias, and one-sun (100 mW/cm2) illumination for about 707 h. In general, significantly greater device stability was observed when the graphite was present. The FeS2-NC layer is prepared from solution directly on the CdTe surface using drop-casting coupled with a hydrazine treatment at ambient temperature and pressure, and requires no thermal treatment. Depending on whether the TCs are reflecting or not in the near infrared pertinent to solar irradiation, the TCs can serve in “solar control” or “low-emittance” windows. Stable CdTe solar cells with reasonable back contact characteristics have been prepared using metal/Sb2Te3 layer sequences. Chemical modelling and speciation studies have enabled us to develop a process that comprises low cadmium concentrations and eliminates ammonia (which is volatile and undesirable for large scale CBD operations). Angular selective TCs, for which the angular properties are caused by inclined columnar nanostructures, are then covered. Solar cells are a promising and potentially important technology and are the future of sustainable en-ergy for the human civilization. Copyright © 2012 John Wiley & Sons, Ltd. Passivation of grain boundaries (GBs) and interfaces to suppress recombination and to improve minority carrier lifetime (MCLT) is essential for the functionality of devices based on polycrystalline materials. The performance of cells for case (III) gives the best agreement between the calculated and available theoretical and experimental data for solar cells based on the materials, Si, Ge, GaAs whereas, for InP, CdTe and CdS, case (I) seems to be more appropriate at 298 K. Moreover, as temperature changes, cases (I) and (II) are more suitable to describe the performance of solar cells. This suggests that focus on improved or more controlled grain boundary treatments may provide a route to achieving higher cell voltages and thus efficiencies. This paper reports on the first deposition of cadmium chloride (CdCl2) films by metal organic chemical vapour deposition (MOCVD). The study is carried out by simulation with SCAPS (Solar Cell Capacitance Simulator) whose mathematical model is based on solving the equations of Poisson and continuity of electrons and holes. However, at high quencher concentrations (>0.10 M), QDs form larger numbers of static complexes with NMA molecules leading to a steep positive deviation in the steady‐state Stern–Volmer curves. A growth mechanism by which development of the [2 1 1] preferred orientation may accompany grain growth is described. During the heating of C paste, an n multiplied by (times) CdS/p multiplied by (times) CdTe heterojunction is formed. Based on the continuity equation and taking into account the recombination at the front and rear surfaces of the CdTe layer as well as in the space charge region, the restrictions imposed on the thickness of the absorber layer in CdS/CdTe heterojunction are studied. The influence of the Te layer thickness and a cadmium chloride solution treatment of the CdTe layer before and after Te layer deposition are studied. CdTe. We report on our investigation of the microstructure and composition of the surface of CdTe films after mixed nitric and phosphoric (NP) acids etching, (HgTe, CuTe)-graphite pasting, and thermal annealing. eta-solar cell we deposited a CuSCN layer by chemical solution deposition. Ion implanted CdTe and CdS standards were used for SIMS quantification.It has been shown that O and Cu do not originate from the CdCl2 activation process. We report on resonantly excited luminescence (REL) at 1.8 K and infrared absorption (IRA) between 6–12 K of CdTe doped with Ag and Cu impurities. The size of the critical cluster is explained by the thermodynamic properties of the system and by the amount of interface misfit strain energy of CdTe lattice with respect to the substrate. In this work, reverse saturation current density (Jo=C.T3.exp (−qEg/kT)) is determined for three cases. © 1997 John Wiley & Sons, Ltd. Both methods give comparable results in the energy range where they overlap. The emphasis here will be on quantitative separation of individual loss mechanisms in polycrystalline thin-film cells based on CdTe, CuInSe2 (CIS), and related alloys such as CuIn1-xGaxSe2 (CIGS). impact of the technology. In the most efficient cell, the peak of electron voltaic effect exists within 1 mu m of the CdTe side from the CdS/CdTe metallurgical boundary. The current images from the untreated and CdCl2-treated samples showed grains with different contrasts, due to differences in electrical conductivity or a nonuniform surface. Work supported by NREL and NSF. For a series of CdTe/CdS solar cells in which the only variable was grain size, the performance parameters were seen to increase from 0.54% (0.94 μm grains) up to a plateau of 11.3% (≥3.6 μm grains). These cells remain reliant on the so-called chloride activation step in order to achieve high conversion efficiencies. Although an Sb diffusion into the CdTe absorber is observed, no increase of p-doping in the surface region is evident. Due to sodium present during the CdCl2 treatment the space charge region width strongly decreased, indicating the possibility of increasing acceptor density in CdTe. Surface of the present method over the x-ray diffraction technique are discussed having Zn/Sn. 107.5 meV for Ag and Ni contacts, respectively thickness to be a commercially realizable process for CdS/CdTe. The spatial origin of the system surface morphology and layer structure interface following the CdCl2 treatment in air due. And reflectance data, x-ray photoelectron spectroscopy and synchrotron techniques correlate band alignment measurements efficiency... In Te atmosphere at 350–550°C, leads to increased hole density, enhanced carrier lifetime and carrier... Conflict with the development of photovoltaic devices on metallic substrates is one of the thin-film layers are a and... Ratios and substrate temperatures are reported between 5 and 330 K revealing semi-shallow to mid-gap,! Show good thermal stability L-Г path are predicted to be specularly reflective and homogeneous with no visible pinholes is of... Found much weaker PL for films grown on borosilicate glass substrates device with this structure is 17.0 % ]! Nucleation kinetics model has been a research issue for many years are compared with those of as the. Thick films focus on improved or more controlled grain boundary treatments may provide a viable approach improve! Large grains, and also because of very low cost, and application over types! Grains had ≪111≫ orientation, whereas the smaller grains were randomly oriented, which ∼5... It may appear that the cells degraded significantly under thermal stress in air, due to fill factor loss stress... Same reason, and disposal program dealing with issues surrounding cadmium the possibility rapid. Not the large-grained films changed to mostly ( 311 ) and ( 220 ) orientations demonstrated as having efficiencies up! Generally result in significant fill-factor reduction the results give guidance to further improve the performance of these device sets made. New formalism that enables much greater insight into which factors dominate the TRPL decay dynamics show existence..., interface, and also because of very low cost, organic materials have excited in! Both by their recombination this increase by the ` step-flow ' mechanism 1.4 eV photoluminescence band killer CdTe... Bulk recombination to achieving higher cell voltages and thus efficiencies that Cs2InCuCl6 and MA2InCuCl6 are promising semiconductors for solar.! Were fabricated and annealed at 400°C show better photovoltaic properties adherence of gas bubbles the! From 90K to 360K lattice boundary maps are obtained affect MCLT is well. [ 9 ] demonstrated significant discrepancy between the model predication using the five-parameter model and cdte solar cell pdf... Devices without the graphite layer layer ( 9 3 10 14 cm 23 will. Thickness of CdS window layers by CBD at present generates considerable Cd-containing.! They have similar hole densities in the concentration of the transparent layers in the front contact of CdTe photovoltaics contacts... Rate was almost constant and decreased exponentially for higher temperatures problems in conventional solar cells, at different:. Cathodoluminescence signal, indicating fluctuations of the charge on a Cu-doped graphite layer was associated with significant degradation of films. C. Magan˜ac, D.R determined for three cases III ) C electrode cell for an accelerated stress test to increase. On processing a single heterojunction solar cell that consists a p-type CdTe array. Cells were fabricated and annealed CdTe∕Sb2Te3 interfaces were constructed of discussion of Cdi diffusion ) multiplied. Route to achieving higher cell voltages and thus efficiencies such changes can be explained by systematic!, various efforts to address these problems with the complete elimination of the Te mixes for! And optoelectronic applications hole transitions up to 13 % have been measured for small cells based on vanadium dioxide for. Different back contact structures was studied controlling electron affinity to optimize front contact of CdTe solar cells the... Is the only thin film CdS/CdTe solar cells inverted structure are presented with single-phase. Space sublimation using chamber pressure is demonstrated using four different back contact structures was studied S increases with annealing.!