Analysis of Photoresponse and Charge Transport Properties of Hydrothermally Synthesized ZnSe Nanoparticle Based Schottky Device


Authors: Arka Dey, Samit Kumar Ray

Last Update 28 Jan 2020

Abstract :

In the present study, ZnSe nanoparticles (NPs) have been successfully synthesized via a hydrothermal process. Sample characterization has been done using Powder X-ray diffraction, UV–Vis spectroscopy, and Field emission scanning electron microscopy. ZnSe NPs show significant optical absorption in the visible light range and the direct optical energy bandgap has been measured as 3.22 eV, which shows the clear blue shift of 0.5 eV from the standard bandgap for bulk ZnSe (Eg = 2.7 eV). Hence, Al/ZnSe metal-semiconductor (MS) junctions have been fabricated to study the electrical properties. The obtained current density-voltage (J-V) characteristics revealed that the thin film devices have non-linear behaviour like Schottky diode (SD). The thermionic emission is the main phenomenon for current transport across these barriers. Here I have measured series resistance (RS), ideality factor (η), barrier height (Φb) and photosensitivity for the fabricated devices under dark and irradiation conditions and also compared those accordingly. The photosensitivity of the Al/ZnSe SD has been found to be 2.85. For the better realization of charge transport phenomena through the MS junction, space charge limited current (SCLC) theory has been employed. The effective mobility of the carrier has been evaluated in dark and light condition as 3.01 x 10-3 and 8.58 x 10-3 m2V-1s-1, respectively. It has been observed that all the electrical properties improved under illumination condition shows its probable application in photosensitive devices.