Photoelectrochemical investigations on vacuum deposited n-CdSe0.6Te0.4 thin film/polysulphide photoelectrochemical solar cells using stainless steel substrates

Abstract

Thin films of n-CdSe0.6Te0.4 of thickness ≈500 nm were deposited by vacuum flash evaporation on highly conducting, precleaned stainless steel substrates (thickness = 2 mm) kept at 473 K at a pressure of 6.6 × 10−3 Pa. The as-grown films exhibited photoactivity in (aq) 1 M NaOH1 M Na2S1 M S (pH = 12.6) The onset of photocurrent with increase in applied electrode potential on illumination of the photoelectrochemical cell at an intensity of 100 mW/cm2 white light yielded a flat band potential of ≈−1200 mV versus saturated calomel electrode (SCE). It was found from the power output characteristics that the efficiency of the photoelectrochemical (PEC) cell using as- grown films on these substrates was about 2.2%. Using Gärtner's Model, the donor concentration and the minority carrier diffusion length were found to be 3.43 × 1017 cm−3 and 0.046 μm respectively which indicated the good rectifying nature of n-CdSe0.6Te0.4 thin film/ polysulphide junction and large grain size and good conductivity of the stainless steel substrate.