scholarly journals Effect of Annealing on the Properties of Antimony Telluride Thin Films and Their Applications in CdTe Solar Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Zhouling Wang ◽  
Yu Hu ◽  
Wei Li ◽  
Guanggen Zeng ◽  
Lianghuan Feng ◽  
...  
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Contact Layer ◽  
Buffer Layers ◽  
Antimony Telluride ◽  
X Ray ◽  
Cdte Solar Cells ◽  
Structural And Electrical Properties ◽  
Different Temperatures ◽  
P Type

Antimony telluride alloy thin films were deposited at room temperature by using the vacuum coevaporation method. The films were annealed at different temperatures in N2ambient, and then the compositional, structural, and electrical properties of antimony telluride thin films were characterized by X-ray fluorescence, X-ray diffraction, differential thermal analysis, and Hall measurements. The results indicate that single phase antimony telluride existed when the annealing temperature was higher than 488 K. All thin films exhibited p-type conductivity with high carrier concentrations. Cell performance was greatly improved when the antimony telluride thin films were used as the back contact layer for CdTe thin film solar cells. The dark current voltage and capacitance voltage measurements were performed to investigate the formation of the back contacts for the cells with or without Sb2Te3buffer layers. CdTe solar cells with the buffer layers can reduce the series resistance and eliminate the reverse junction between CdTe and metal electrodes.

scholarly journals Properties of Arsenic–Doped ZnTe Thin Films as a Back Contact for CdTe Solar Cells

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3706 ◽  
Author(s):  
Ochai Oklobia ◽  
Giray Kartopu ◽  
Stuart J. C. Irvine
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Open Circuit ◽  
Activation Process ◽  
Back Contact ◽  
Contact Activation ◽  
Doping Density ◽  
Cdte Solar Cells ◽  
Absorber Doping ◽  
P Type

As-doped polycrystalline ZnTe layers grown by metalorganic chemical vapor deposition (MOCVD) have been investigated as a back contact for CdTe solar cells. While undoped ZnTe films were essentially insulating, the doped layers showed significant rise in conductivity with increasing As concentration. High p-type carrier densities up 4.5 × 1018 cm−3 was measured by the Hall-effect in heavily doped ZnTe:As films, displaying electrical properties comparable to epitaxial ZnTe single crystalline thin films in the literature. Device incorporation with as-deposited ZnTe:As yielded lower photovoltaic (PV) performance compared to reference devices, due to losses in the open-circuit potential (VOC) and fill factor (FF) related to reducing p-type doping density (NA) in the absorber layer. Some minor recovery observed in absorber doping following a Cl-free post–ZnTe:As deposition anneal in hydrogen at 420 °C contributed to a slight improvement in VOC and NA, highlighting the significance of back contact activation. A mild CdCl2 activation process on the ZnTe:As back contact layer via a sacrificial CdS cap layer has been assessed to suppress Zn losses, which occur in the case of standard CdCl2 anneal treatments (CHT) via formation of volatile ZnCl2. The CdS sacrificial cap was effective in minimising the Zn loss. Compared to untreated and non-capped, mild CHT processed ZnTe:As back contacted devices, mild CHT with a CdS barrier showed the highest recovery in absorber doping and an ~10 mV gain in VOC, with the best cell efficiency approaching the baseline devices.

scholarly journals Material Requirements for Buffer Layers Used to Obtain Solar Cells with High Open Circuit Voltages

1999 ◽  
Vol 557 ◽  
Author(s):  
Bolko Von Roedern ◽  
Gottfried H. Bauer
Keyword(s):  
Solar Cells ◽  
Transparent Conductive Oxide ◽  
Contact Layer ◽  
Open Circuit ◽  
Buffer Layers ◽  
Hit Cells ◽  
Type C ◽  
P Type ◽  
Open Circuit Voltages ◽  
Material Requirements

AbstractThis paper discusses material requirements for junction layers needed to obtain solar cells with highest possible open-circuit voltages (VOC). In a typical a-Si:H-based “p/i/n” solar cell, this includes the transparent conductive oxide (TCO) contact layer, the p-layer, a “buffer layer” inserted at the p/i interface, and the surface portion of the intrinsic layer. In HIT-cells, the i-layer between (n-type) c-Si and (p-type) a-Si:H may be regarded as the buffer. Our suggestion to obtain high values of VOC relies on using materials with high lifetimes and low carrier mobilities that are capable of reducing surface or junction recombination by reducing the flow of carriers into this loss-pathway. We provide a general calculation that supports these approaches and can explain why these schemes are beneficial for all solar cells.

scholarly journals Structural and Electrical Properties Dependence on Annealing Temperature of Bi Thin Films

2014 ◽  
Vol 11 (3) ◽  
pp. 1257-1260
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Annealing Temperature ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Structural And Electrical Properties ◽  
Evaporation Technique ◽  
P Type

In this work the effect of annealing temperature on the structure and the electrical properties of Bi thin films was studied, the Bi films were deposited on glass substrates at room temperature by thermal evaporation technique with thickness (0.4 µm) and rate of deposition equal to 6.66Å/sec, all samples are annealed in a vacuum for one hour. The X-ray diffraction analysis shows that the prepared samples are polycrystalline and it exhibits hexagonal structure. The electrical properties of these films were studied with different annealing temperatures, the d.c conductivity for films decreases from 16.42 ? 10-2 at 343K to 10.11?10-2 (?.cm)-1 at 363K. The electrical activation energies Ea1 and Ea2 increase from 0.031 to 0.049eV and from 0.096 to 0. 162 eV with increasing of annealing temperature from 343K to 363K, respectively. Hall measurements showed that all the films are p-type.

Cu K-edge EXAFS Studies Of CdCl2 Effects On CdTe Solar Cells

2005 ◽  
Vol 865 ◽  
Author(s):  
Xiangxin Liu ◽  
Alvin D. Compaan ◽  
Jeff Terry
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Grain Boundary ◽  
Cdte Thin Film ◽  
X Ray ◽  
Cdte Solar Cells ◽  
Cdte Films ◽  
Chloride Treatment ◽  
P Type ◽  
X Ray Absorption

AbstractThe highest performance CdS/CdTe thin film solar cells are generally completed with a Cucontaining back contact. The copper appears to be critical for achieving heavy p-type doping of the CdTe at the contact to permit the formation of a low resistance contact. In previous extended x-ray absorption fine structure (EXAFS) work we have inferred that most of the Cu in CdTe films resides as Cu2O at the boundaries of CdTe grains in films that have received a chloride treatment in the presence of oxygen, a critical step needed to improve the performance of all CdTe thin-film cells. This has suggested a mechanism for grain boundary passivation in thinfilm CdTe solar cells. We believe most of the diffused Cu decorates grain boundaries as oxides, consistent with the low doping densities typically observed in CdTe solar cells. The significance for grain boundary passivation will be discussed. We also find evidence that the grain-boundary Cu2O in CdCl2 treated CdTe films is unstable and tends to transform to CuO under some stress conditions.

Influence of Annealing Temperature on the Properties of Zn-Sb Composite Thin Films by Magnetron Sputtering

2015 ◽  
Vol 1096 ◽  
pp. 76-79
Author(s):  
Yu Huan Sun ◽  
Juan Qin ◽  
Guo Hua Wang ◽  
Wei Min Shi
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Composite Thin Films ◽  
X Ray ◽  
Hall Measurements ◽  
Different Temperatures ◽  
Diffraction Patterns ◽  
Increasing Temperature ◽  
P Type

Zn-Sb based composite thin films have been prepared by radio frequency magnetron sputtering using a Zn4Sb3 compound target followed by thermal annealing. Sample structure and surface morphology were analyzed by X-ray diffraction (XRD) and atomic force microscopy (AFM). The electrical properties of the films were studied by Hall measurements. The X-ray diffraction patterns reveal that the intensity of diffraction peak of ZnSb phase is enhanced as temperature increasing. Results of AFM shows the rms roughness is getting big with increasing temperature due to the growing crystal grains. Hall measurements indicate that the Zn-Sb composite thin films annealed at different temperatures are p-type conducting with carrier concentrations being on the order of 1019 cm-3.

Thermally evaporated CdS thin films for CdS/CdTe solar cells: Effect of substrate temperature on CdS layer

2021 ◽  
Vol 273 ◽  
pp. 115406
Author(s):  
A.A.I. Lakmal ◽  
R.K.K.G.R.G. Kumarasinghe ◽  
V.A. Seneviratne ◽  
Jiann-Yeu Chen ◽  
Jenn-Ming Song ◽  
...  
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Substrate Temperature ◽  
Cdte Solar Cells ◽  
Cds Thin Films

scholarly journals C-VCalculations in CdS/CdTe Thin Films Solar Cells with aCdSxTe1-xInterlayer

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
A. Gonzalez-Cisneros ◽  
F. L. Castillo-Alvarado ◽  
J. Ortiz-Lopez ◽  
G. Contreras-Puente
Keyword(s):  
Experimental Data ◽  
Thin Films ◽  
Solar Cells ◽  
Photovoltaic Cells ◽  
Cdte Film ◽  
Vapor Transport ◽  
Cdte Solar Cells ◽  
Cdte Thin Films ◽  
Cds Film ◽  
Theoretical Results

In CdS/CdTe solar cells, chemical interdiffusion at the interface gives rise to the formation of an interlayer of the ternary compoundCdSxCdTe1-x. In this work, we evaluate the effects of this interlayer in CdS/CdTe photovoltaic cells in order to improve theoretical results describing experimentalC-V(capacitance versus voltage) characteristics. We extended our previous theoretical methodology developed on the basis of three cardinal equations (Castillo-Alvarado et al., 2010). The present results provide a better fit to experimental data obtained from CdS/CdTe solar cells grown in our laboratory by the chemical bath deposition (for CdS film) and the close-spaced vapor transport (for CdTe film) techniques.

Synthesis of high-quality ZnTe:Cu films as a back contact layer for CdTe solar cells

2021 ◽  
Author(s):  
Xinlu Lin ◽  
Yufeng Zhang ◽  
Ziyao Zhu ◽  
Qiuchen Wu ◽  
Xiangxin Liu
Keyword(s):  
Solar Cells ◽  
Contact Layer ◽  
Back Contact ◽  
High Quality ◽  
Cdte Solar Cells
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