Optical and photoelectric properties of layered semiconductor Zn8In16S32

Full text: To number of perspective multicomponent semiconductors the numerous class of ternary compounds II-III2-VI4 (where, II divalent cations - Mn, Pb, Hg, Zn; III - trivalent cations - Ga, In; VI - chalcogenides - S, Se) initial researches which have already led to detection among them new perspective materials for application in optoelectronics. In this paper we report the results of investigation of photoluminescence (PL), optical absorption and photoelectric properties of Zn8In16S32 (Zn8In16S32=8ZnS+8In2S3) single crystals grown by Bridgman method and having hexagonal structure with lattice parameters: a=3.86; c=36.95 A and space group P63mc-C6v4. Optical absorption spectra of Zn8In16S32 were recorded at 300 K. Obtained data show that optical transition in our samples are indirect with bang gap, Egi=1.533 eV (300 K). PL spectrum of Zn8In16S32 crystals consist of one emission band with a peak at 650 nm at low temperatures. The intensity decreases with increasing temperature. Photoelectric spectrum of In/Zn8In16S32 structure have been measured in the photon energy range 1.24-3.1 eV in various electrical field. The spectral response exhibits one intensive maximum at 2.51 eV at an illumination from crystal side. This semiconductor is photosensitive, with resistivity changing (ρl/ρd) by 4 order of magnitude in the voltage range of ohmic behavior at an illuminance of 100 lx. Photocurrent strongly depends from applied electrical field