The photoelectrochemical properties of 'Q-state' CdSx Se(1-x) particles in Langmuir-Blodgett films deposited onto optically transparent glass electrodes (OTE)

CdS 'Q-state' particles, with average diameters varying from 2 nm to 10 nm, grown in arachidic acid Langmuir-Blodgett (LB) films, deposited onto optically transparent glass electrodes (OTES), were exposed to H2 Se(g) to form the corresponding Q-state Cd Sx Se(1-x) particles. Those particles are considered to be made up of a core of CdS and coated with a monolayer of Cd Se. Q-state Cd S-x Se(1-x) particle formation was verified by X-ray photoelectron spectroscopy (XPS) and by monitoring a red shift in the UV-visible absorbance spectra relative to that of Cds. XPS results on 5 nm diameter CdS particles that had been grown in an LB film and then extensively exposed to H2 S (g) revealed a stable average composition of Cd S0.4 Se06. A study of the photoelectrochemical behaviour of these systems was conducted through current the open-circuit voltage and a marked increase in the short-circuit current was observed when LB films with Q-state CdS particles were exposed to H2 Se(g). (author)