Self-powered anisotropic photo-responsive properties of tin mono-selenide (SnSe) photodetector

Transition metal chalcogenides (TMCs) have been extensively investigated due to their pervasive range of properties for the fabrication of several next-generation optoelectronic devices including flexible detectors, photodetectors, and photo sensors. This article reports the growth, characterization, and photodetection and response study of crystalline tin selenide (SnSe) grown by the direct vapor transport (DVT) technique. The stoichiometric confirmation of as-grown compound tin mono-selenide (SnSe) was confirmed by EDAX spectra. Structural confirmation was carried out using powder X-Ray Diffraction (PXRD). The bandgap of the grown crystals was also calculated from Tauc's plot. Anisotropic photodetection study of the SnSe photodetector demonstrates the superior photocurrent of 0.62 μA under polychromatic light for the I-II configurations of contacts. The stability of isotropic configuration is also observed to be high compared to anisotropic configuration. The results suggest isotropic contact configuration is most preferable for the SnSe photodetector. We observed that, under zero biasing conditions, the device performance improves, which indicates that the fabricated photo-diode exhibits an adequate photosensitive nature. It is observed that the device performs wisely under the self-driven condition, which points out the adequate photo-conductive (photo-self-driven) nature of the detector.