Rapid Chemical Bath Depositions and Properties of SnS Films

Abstract

Tin sulfide films were deposited from an aqueous solution of tin dichloride, thiacetamide, and disodium citrate. X-ray diffraction, atomic force microscopy, ultraviolet–visible spectrophotometry, and electrical measurement were used to characterize the films. The films directly deposited at 70 and 80 °C for 1 and 2 h showed thicknesses of 70–400 and 120–650 nm, respectively. But the deposition at 40 °C for 1 h (nucleation step) made the films subsequently deposited at 60–80 °C denser and thicker (∼1600–7500 nm) than directly deposited films. Average transmittances of the films in UV–visible range decrease with increase in the thickness and are only in range of 0.33–2.3% for the films deposited with the nucleation step. The band gap energies of the films estimated from the transmittance spectra are in the range of ∼1.37–1.55 eV. Moreover, the films are p-type conductive. The electrical resistance and carrier mobility are in the ranges of 0.3–1.4 × 105 Ω cm and 0.77–1.56 cm2 (V s)−1, respectively. The films deposited with the nucleation step show lower resistance and higher carrier mobility than those deposited without nucleation because of their denser film microstructure and larger film thickness.