Electrodeposited tin selenide thin films for photovoltaic applications

摘要

Tin selenide thin films of about 300 nm thickness were electrodeposited on SnO_2:F coated transparent conductive oxide glass substrates. The optimum deposition potential was determined from cyclic voltammetry measurements. The films were polycrystalline with orthorhombic structure and the grain size was about 18 nm. SEM images showed a highly porous film structure. The band gap estimated from optical spectra of these films showed absorption due to direct transition occurring at 1.1 eV. Characteristic vibrational modes of the SnSe were observed in the Raman spectrum. The films are p-type, photosensitive, and the conductivity measured in dark was in the range of 10~(-5) Ω~(-1) cm~(-1). A prototype CdS/SnSe photovoltaic device showed an open circuit voltage of 140 mV and short circuit current density 0.7 mA/cm~2.