Synthesis characterization of SnO2 nanofibers (NFs) and application of high-performing photodetectors based on SnO2 NFs/n-Si heterostructure

Abstract

We report a photodetector consisting of electrospun SnO2 nanofibers (NFs) on an n-type Si wafer as the SnO2 NFs/n-Si heterojunction architecture. The microstructure analysis of the SnO2 NFs was determined by utilizing the advanced X-ray diffraction approach (WPPM). The DRS spectrum and detailed photoluminescence (PL) measurements have been carried out to study the optical properties. In addition, the current-voltage, frequency-dependent capacitance/conductance-voltage, and voltage-dependent capacitance-frequency measurements of the SnO2 NFs/n-Si device were analyzed in the dark. From the dark I-V measurements, the rectification ratio, reverse current, ideality factor, and barrier height were determined as 19631 (at ± 2 V), ~2.5 × 10−9 A (at - 2 V), 2.56, and 0.85 eV, respectively. Furthermore, the shunt resistance (Rsh) (at −2 V) and series resistance (Rs) (at +2 V) of the device were calculated as ~1.1 GΩ and ~2.8 kΩ, respectively from the dark I-V graphs. For the photodetector characteristics of the SnO2 NFs/n-Si device, the light intensity-dependent I-V measurements ranged from 20 mW/cm2 to 150 mW/cm2 were carried out in visible light in addition to UV light (365 nm and 395 nm). Experimental Rsh and Rs were also determined as a function of light intensity. The device's ON/OFF ratio, the detectivity, and the responsivity reached as high as 9576, 1.38 × 1011 Jones, and 0.66 A/W for 150 mW/cm2., at − 1.5 V.