Electrodeposition of stoichiometric CdTe thin film for photovoltaic application

Abstract

Theoretical model based on the Buler-Volmer equation was developed to obtain the potential of perfect stoichiometry (PPS) under a variety of deposited conditions, and results were confirmed experimentally. It also shows that the stoichiometric deviation of CdTe thin film can be controlled accurately. The simulation of electrodeposited process for CdTe was conditioned in the acidic electrolyte containing reducible ions of Cd2+ and HTeO2+. Based on the simulated predictions, well-connected granular CdTe thin films were deposited at PPS. Due to near stoichiometric sample shows slightly p-type, the concentration of HTeO2+ ion was then decrease to reach more intrinsic condition under the PPS applied. Particularly, the p-type, near i-type and n type of CdTe thin films can be electrodeposited se-quentially. The thickness of each layers deposited was achieved by varying the applied potential with different deposited time.

Effect of the Cadmium Telluride Deposition Method on the Covering Degree of Electrodes Based on Copper Nanowire Arrays

“…The CdTe film was grown by applying −0.5 V versus an Ag/AgCl reference electrode (KCl-saturated, E = 0.197 V against NHE), while the process temperature was maintained at 60 • C. As is well known, ECD is typically a low-temperature process when compared to the VTE or RF-MS alternatives, allowing CdTe thin films with good structural properties to be obtained at temperatures even below 60 • C [28]. The overall electrochemical growth of CdTe has been commonly reported to occur in two steps, with the cathodic reduction of HTeO + 2 to Te (Equation ( 1)) subsequently accompanied by the temperature-mediated reaction of Te with Cd 2+ (Equation ( 2)), ultimately favoring CdTe formation [32,33]:…”

Correlation of microscopic grain evolution in post‐CdCl 2 annealing and performance of CdS/CdTe thin‐film solar cells fabricated using pulsed laser deposition

“…Nevertheless, smaller thickness is preferred to minimize the charge recombination effect and reduce the material cost . In addition, most previously reported CdTe/CdS solar cells employ ex situ processes for fabrication of the CdS window and CdTe absorber layers separately using different approaches , which are prone to the risk of the CdS/CdTe interface contamination and not suitable to thin‐film (thickness around 1 μm) CdS/CdTe solar cells. These have motivated researches in exploring alternative approaches for in situ fabrication of thin‐film CdS/CdTe solar cells and considerable progress has been made in application of magnetron sputtering and pulsed laser deposition (PLD) for this purpose .…”