Anisotropic study of photo-bolometric effect in Sb0.15Ge0.85Se ternary alloy at low temperature

To foster high-performance optoelectronic devices, alloy engineering has shown great potential for synthesis of the materials. Here, we demonstrate the effect of Sb doping on structural and optoelectronic properties in GeSe multi-layered single crystals synthesized by DVT. The stoichiometric proportion of elements was determined by EDAX. The orthorhombic structure of the compounds was confirmed by XRD, the increase in lattice volume inveterate successful substitution of Sb+3 on Ge+2 lattice sites. The substitution was reassured by the blue shift in the vibrational mode peaks of Raman spectra. Successively, the dynamic I-t characteristics of the ternary alloys based photodetectors were studied. Among all, Sb0.15Ge0.85Se ternary alloy showed negative photo-response under the illumination of different monochromatic lights, due to amplified carrier-phonon interactions as a result of high lattice strain. Owing to the layered structure of transition metal chalcogenides, the anisotropy in the dynamic I-t characteristics was studied. The compound showed higher photo-response for the contacts taken parallel to c-axis than connections made perpendicular to c-axis because of higher effective mass in the later configuration. Anisotropic photo-response was also studied at low temperatures in the range 300 K-100 K. The investigation presents a novel photo-response for application in the field of photodetection. (C) 2020 Elsevier B.V. All rights reserved.