PROPERTIES OF INDIUM DOPED CdS THIN FILMS AND THEIR PHOTOVOLTAIC APPLICATION IN CdTe SOLAR CELLS.

Cadmium sulfide thin films with different doping concentration of indium were deposited by magnetron sputtering. The effects of indium concentration on the structure, electrical and optical properties of CdS thin films were studied. XRD results show that all In-doped CdS thin films mainly have face-centered cubic structure with preferred orientation in (111) direction. The optical band gap of CdS:In films varied with indium concentration while the average grain size has an opposite dependency on indium. The carrier concentration increased by 1~3 magnitudes with indium concentration. CdTe solar cells based on CdS:In window layer were fabricated to verify the doping effect of indium on CdS thin films. Photo current density-voltage characteristics and EQE spectra suggest that indium can effectively enhance the collection of carriers in depletion area, which leads to improve both Voc and Jsc. Indium doped CdS layer coupled with standard CdTe preparation process has yielded up to 15.53% efficiency solar cell on commercialized TCO substrates. [ABSTRACT FROM AUTHOR]