Abstract: Chemical Bath Deposition (CBD) technique is employed in depositing prepared Lead Sulphide (PbS) as thin film on glass substrates at varied deposition time. The durations of our deposition are 180, 240 and 300 min. We annealed some prepared samples at 100, 150 and 200°C so as to modify their grain boundaries and the remaining samples were left, as they were prepared. The `as prepared` and `annealed` PbS samples are then studied. We measured and recorded the transmittance of each sample at various wavelengths between 400 and 1000 nm using Visible/Ultra-violet Spectro-photometer model, 6405. The effect of deposition time on transmissivity of Lead sulphide is observed. The result shows non-linear relationship between the deposition time and transmissivity of PbS sample. The deposition time of `as prepared` PbS samples increases as transmissivity increases up to an optimum point of transmissivity between 230 and 240 min after which the transmissivity nearly remains constant with further increase in deposition time. The annealed samples initially show increase in transmissiviy with an increasing deposition time but beyond a specific time, termed `critical deposition time`, the transmittance decreases as deposition time increases. Thus, the optimum transmissivity of annealed PbS thin film occurs at this `critical deposition time` (between 235 and 245 min) beyond which the transmittance decreases with further increase in deposition time. Hence, the deposition time is then considered to have great influence on the transmissivity of chemically deposited Lead Sulphide (PbS) thin film and thus influence its electrical and optical characterization.
J.A. Amusan , G.R. Fajinmi , Y.K. Sanusi and S.A. Okewoye , 2007. Effect of Deposition Time on Transmissivity of Chemically Deposited Lead Sulphide Thin Film. Research Journal of Applied Sciences, 2: 1170-1173.