Characterizations of Spray Deposited CdTe Thin Film

The spray pyrolysis is promising technique for deposition of CdTe thin film. We deposited CdTe thin film on glass substrate by homemade spray pyrolysis technique at substrate temperature 3000C. The CdTe thin film was characterized through Field scanning electron microscopy (FSEM), Energy dispersive X-ray analysis (EDAX), Uv-Visible spectroscopy. The SEM micrograph shows the film was uniform coverage, large number of densely packed grain whosesizes ranging from 474nm to 1.64µm. From EDAX analysis conform that the presenceof Cd and Te in prepared film with elemental stoichiometry of Cd and Se was 50.28% and 49.72% respectively. The optical absorption coefficient of the film of order of 106 and band gap of the film 1.45eV.

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

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.