Preferred Abstract (Original):
This communication describes
how annealing under nitrogen affects photo-electrochemical characteristics of
films deposited from authentic Cu
2SnSe
3 sources by vacuum
evaporation under argon gas (low flow rate 5 cm
3/min) using substrate 300 °C. Annealing
lowered the photoresponse of the deposited film, by affecting crystallite
structure, morphology, composition and pores in the films. Annealing at
temperatures in the range 150 - 350 °C improved
crystallinity of the film but lead to pore formation between adjacent, which lowered
photoresponse by increased resistance across the electrode/redox interface. Annealing
at higher temperature (450 °C) lead to the formation of the
SnO
2, as an additional phase, at the expense of Cu
2SnS
3
decomposition. Porosity and mixed phases with SnO
2 presumably
increased film internal resistance and resulted in poor charge transfer across
the solid/redox couple interface. By affecting film characteristics, annealing
lowered photoresponse for the deposited films.