Effect of O2 on thickness uniformity of CdTe thin film deposited using CSS

2009 ◽  
Vol 1210 ◽  
Author(s):  
Nirav D Vora ◽  
Ramesh Dhere
Keyword(s):  
Thin Film ◽  
Element Model ◽  
Cdte Film ◽  
Cdte Thin Film ◽  
Cell Efficiency ◽  
Steady State Model ◽  
Closed Space Sublimation ◽  
Effect Of Oxygen ◽  
Heat Transfers ◽  
Space Sublimation

AbstractIncorporating O2 in the closed space sublimation (CSS) of CdTe thin film has resulted in improved cell efficiencies. Many studies have been undertaken to understand this effect on cell efficiency. In this work we study the effect of oxygen on lateral uniformity of the deposited CdTe film. A finite element model has been developed to represent the mass and heat transfers involved in the CSS process. The model takes into consideration the effect of O2 by modeling its reaction with Cd vapors in the space between the source and the substrates and with the CdTe source. So a gradient of O2 from the edges to the center of the substrate can result in non-uniform oxidation of the source and subsequently a laterally non-uniform film. A steady state model solved at various temperatures, pressures, and separation distances. O2 concentration gradient was found to depend on the oxidation rate of Cd vapors and thus on temperature, total pressure, and oxygen partial pressure in the system.

Texture-tuned growth of CdTe thin films by closed-space sublimation technique

2008 ◽  
Vol 23 (1) ◽  
pp. 31-34
Author(s):  
Shang Fei ◽  
Ji-kang Jian ◽  
Wu Rong ◽  
Zheng Yu-feng ◽  
Sun Yan-fei
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Absorption ◽  
Band Gaps ◽  
Cdte Thin Film ◽  
Closed Space ◽  
Heating Current ◽  
Closed Space Sublimation ◽  
Cdte Thin Films ◽  
Space Sublimation

CdTe thin films were grown on indium tin oxide glass substrates by a closed-space sublimation method using a resistor heater. Crystalline structure, morphology, and band gaps of the films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical absorption, respectively. The XRD analysis showed that the textures of the films were found to depend on the rate of increase in the heating current. The CdTe thin film had an (111) texture when the heating current rate was 2.0 A/min. The SEM analysis revealed that the film is composed of polyhedral grains of microns size. However, the (111) texture of the CdTe thin film observed by XRD decreased with the appearance of (220), (311), (400), (331), (422), and (511) peaks of the fcc CdTe phase when the heating current rate increased to 4.5 A/min. The (111) texture disappeared when the heating current was increased immediately from 0 A to the target current of 70 A. SEM results revealed that the grains in the film are round and the grain size is smaller than 1 μm. Optical absorption analysis showed that there is no distinctive difference in the band gaps of the films.

scholarly journals Влияние отжига во фреоне на кристаллическую структуру слоев теллурида кадмия и эффективность пленочных фотоэлектрических преобразователей на их основе

2019 ◽  
Vol 53 (1) ◽  
pp. 93
Author(s):  
Г.С. Хрипунов ◽  
А.В. Мериуц ◽  
Т.Н. Шелест ◽  
М.Г. Хрипунов
Keyword(s):  
Thin Film ◽  
Cadmium Telluride ◽  
Production Technology ◽  
Thermal Evaporation ◽  
Commercial Production ◽  
Closed Space ◽  
Thermal Vacuum ◽  
Morphological Studies ◽  
Closed Space Sublimation ◽  
Space Sublimation

AbstractSolar cells (SCs) based on cadmium-telluride base layers, obtained by thermal evaporation and closed-space sublimation (CSS), are investigated. The base layers are activated via annealing in Freon. Structural and morphological studies are carried out to compare the recrystallization processes occurring during annealing in CdTе layers fabricated by different methods. The output parameters and light diode characteristics of the SCs are investigated, and the possibility of applying Freon annealing in the commercial production technology of thin-film CdS/CdTе SCs with base layers formed by thermal vacuum evaporation is analyzed.

scholarly journals ZnO thickness and ZnTe back contact effect of CdTe thin film solar cell Voc and efficiency progression

2021 ◽  
Author(s):  
Bablu K Ghosh ◽  
Syafiqa Nasir ◽  
Kenneth Tze Kin Teo ◽  
Ismail Saad
Keyword(s):  
Thin Film ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Simulation Software ◽  
Thickness Effect ◽  
Back Surface ◽  
Back Contact ◽  
Cdte Thin Film ◽  
Cell Efficiency ◽  
Commercial Platform

Abstract CdTe thin film (TF) solar cells are most promising photovoltaic (PV) technology in commercial platform. Back contacts and interface defects related opto-electrical losses are still vital to limit its further technological benefit. TF PV cells shallow recombination and parasitic loss lessening purpose carrier selective back contact with band matching window layers are essential. Beside that back and front contact thickness choice is vital for field associated selective carrier collection and generous optical transmission into the active junction of the cell. It can make variation of cell efficiency. Window and front contact layers band edge variation and back contact thickness effect is analyzed by SCAPS-1D simulation software. ZnO and SnO2 front contact for CdS and CdSe window layers effect are numerically studied for 1 µm CdTe cell. Significance of materials for front contact and its thinness effect on current density while ZnTe back surface field contact thickness effect on open circuit voltage and efficiency are demonstrated. Finally, ZnO/CdS/CdTe/ZnTe cell of 0.925 V open circuit voltage and 19.06% efficiency is achieved for 90 nm of ZnTe with Molybdenum (Mo) back contact.

Improving CdS/CdTe thin film solar cell efficiency by optimizing the physical properties of CdS with the application of thermal and chemical treatments

2015 ◽  
Vol 582 ◽  
pp. 124-127 ◽  
Author(s):  
J.M. Flores-Marquez ◽  
M.L. Albor-Aguilera ◽  
Y. Matsumoto-Kuwabara ◽  
M.A. Gonzalez-Trujillo ◽  
C. Hernandez-Vasquez ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Physical Properties ◽  
Thin Film Solar Cell ◽  
Cdte Thin Film ◽  
Solar Cell Efficiency ◽  
Cell Efficiency ◽  
Chemical Treatments

scholarly journals Impact of CdCl2 Treatment in CdTe Thin Film Grown on Ultra-Thin Glass Substrate via Close Spaced Sublimation

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 390
Author(s):  
Nowshad Amin ◽  
Mohammad Rezaul Karim ◽  
Zeid Abdullah ALOthman
Keyword(s):  
Thin Film ◽  
Annealing Temperature ◽  
Cdte Film ◽  
Treatment Temperature ◽  
Bandgap Energy ◽  
Optimum Process ◽  
Cdte Thin Film ◽  
Thin Glass ◽  
Temperature Range ◽  
Cdcl2 Treatment

In this study, close-spaced sublimation (CSS) grown cadmium telluride (CdTe) thin films with good adhesion to 100 µm thin Schott D263T ultra-thin glass (UTG) were investigated. Cadmium chloride (CdCl2) treatment in vacuum ambient was executed to enhance the film quality and optoelectrical properties of CdTe thin film. The post-deposition annealing temperature ranging from 360–420 °C was examined to improve the CdTe film quality on UTG substrate. Various characterization techniques have been used to observe the compositional, morphological, optical, as well as electrical properties. Scanning electron microscopy (SEM) verified that the CdTe morphology and grain size could be controlled via CdCl2 treatment temperature. Energy Dispersive X-Ray Analysis (EDX) results confirmed that the annealing temperature range of 375–390 °C yielded the stoichiometric CdTe films. UV-Vis analysis estimated the post-treatment bandgap energy in the range of 1.39–1.46 eV. Carrier concentration and resistivity were obtained in the order of 1013 cm−3 and 104 Ω-cm, respectively. All the experimental results established that the CdCl2 treatment temperature range of 390–405 °C might be considered as the optimum process temperature for the deposition of CdTe solar cell on UTG substrate in close-spaced sublimation (CSS) method.

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