Junction and Back Contact Properties of Spray-Deposited M/SnS/In2S3/SnO2:F/Glass (M = Cu, Graphite) Devices: Considerations to Improve Photovoltaic Performance

摘要

SnS/In2S3 heterojunction devices were fabricated entirely by chemical spray pyrolysis in a superstrate configuration on SnO2:F/glass. The SnS/In2S3 junction was found to exhibit strong rectification behavior, and the Mott-Schottky characteristics showed it was abrupt. The photovoltaic behavior of the junction was investigated under air mass 1.5G illumination, showing a short-circuit current of 4.8 mA/cm(2) and an open-circuit voltage of 0.29 V, reportedly the highest to date among similar devices with a Cd-free buffer layer and processed by a nonvacuum technique. However, the device suffers from low fill factor due to high series resistance originating from interface inhomogeneities. A Cu back contact was associated with a low level of inhomogeneities at the interface, as demonstrated by impedance analysis.