Orthorhombic SnSe Nanocrystals for Visible-Light Photodetectors

The two-dimensional pristine tin selenide (SnSe), possessing desirable optical, thermal, electrical, and optoelectronic characteristics, is the future nanomaterial of technological applications. In the present study, SnSe nanosingle crystals were grown using the direct vapor transport (DVT) method. The chemical composition, morphological analysis, crystalline phase, crystallinity, optical properties, vibrational modes, and oxidation states of the elements of the grown crystals are verified by energy-dispersive X-ray analysis (EDAX), X-ray photoelectron spectroscopy (XPS), optical microscopy–scanning electron microscopy (SEM), photoluminescence (PL), Raman, and X-ray diffraction. For the optoelectronic study of grown crystals, the current–voltage characteristic was measured. A photodetector based on single-crystalline SnSe is fabricated and studied under visible light with an on/off period of 10 s. The device designates excellent photocurrent and responsivity. Moreover, the photoelectrochemical (PEC) visible-light photoresponse of the SnSe single crystals was also studied. The photovoltaic output parameters like the open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF), and efficiency (η%) for the cell were determined. The grown crystal shows the highest photocurrent of 1.31 μA under an illumination of 120 mW/cm2. Mott–Schottky plots helped in the redox analysis and energy band location. The Nyquist plot is also plotted to study electrochemical impedance. The work demonstrated the potential application of SnSe nanosingle crystals in the field of optoelectronic visible-light conditions.