Photoelectrochemical behaviour of CdS'Q-state' semiconductor particles in 10,12-nonacosadiynoic acid polymer langmuir-blodgett films

摘要

CdS "Q-state" semiconductor particles from 2 to10nm diameter were nucleated and grown in 10,12-nonacosadiynoic acid (NCDA) polymer Langmuir-Blodgett (LB)films deposited on ITO plates. The polymerization process throughexposure to UV-Visible light resulted in formation of the "blueform" followed by the final "red form" after 60 min. X-rayphotoelectron spectroscopy (XPS) measurements confirmed thedeposition of the NCDA cadmium salt and the formation of theCdS particles after exposure to H2S(g) in the LB matrix. A study ofthe photoelectrochemical behaviour of these systems wasconducted through polarisation current-voltage (I-V) curves in therange of 0 to -1000 mV (Standard Calomel Electrode-SCE). Anaverage open-circuit voltage (VOC) from-600 to -700 mV valueswas observed for photoelectrochemical (PEC) cells constructedfor the undoped NCDA polymer LB film with 10 nm diameterCdS particles. The I2-doped NCDA polymer film presented anincrease in the conductivity compared with the undoped film butwith a deterioration of stability of the PEC system.