Band alignment of differently treated TCO/CdS interface

Abstract Studying the band offset at the interface is essential to design and optimize the front and back contacts to reduce loss of photogenerated carriers in CdTe thin film solar cell. CdS layers were deposited at two different substrate temperatures onto ITO and ITO/SnO2 substrates by close spaced sublimation. Photoelectron spectroscopy and sputter depth profiling was employed to determine the band offset at the TCO/CdS interface with different heat treatments. Our results show that different deposition temperatures and heat treatments including activation in CdCl2 do not significantly alter the band alignment.