A Photoelectrochemical Investigation of the n‐Semiconductors α‐HgS and α‐HgS_1‐xSe_x Solid Solutions

Abstract

Photoclectrochemical investigations are described with solid solution HgS1‐xSex electrodes of the compositions x = 0, 0.01, 0.03, and 0.06. The electrodes were prepared by a sublimation and a vapor phase technique, respectively. The semiconductor electrodes were characterized by their current‐potential dependence and their spectral response as function of illumination time.—No corrosion currents were observed in an aqueous electrolyte of pH 2.5 in the potential vs. SCE region −0.45 to +0.9 V in the dark. Upon illumination only the electrode with the highest selenium content corrodes noticeably. Bandgaps of Eg = 2.1 eV with x = 0 and Eg = 1.7 eV with x = 0.06 are determined from wavelength dependent photocurrent spectra. The results indicate that the transition of the hexagonal α‐ to the cubic β‐structure is more hindered in the solid solution electrodes than in the pure α‐HgS system.