Thin-film photodiode based on novel SiC/MoS2 composite by RF-sputtering for fast response photodetection

Abstract

A Schottky -photodiode and pn-photodiode were fabricated based on a SiC/MoS2 composite semiconductor material using a physical vapour deposition (PVD) method. The surface topology and structural features of the nanostructured SiC/MoS2 thin films were investigated using scanning electron microscope (SEM), Fourier Transform Infrared spectroscopy (FTIR), and grazing incidence X-Ray diffraction (GIXRD) analysis. The two-dimensional nature of these materials enables easiness integration for vertical device design with novel properties. The performance parameters of the fabricated devices were characterized. The electrical performance of the fabricated SiC/MoS2 Schottky and pn photodiodes were investigated according to their current-voltage (I–V) characteristics within a bias voltage range from −4 to 4 V. Here, we report highly efficient photocurrent generation from vertical SiC/MoS2 composite device fabricated using asymmetric metal contacts, exhibiting an external quantum efficiency (EQE) of up to 14.68% for pn -photodiode and 6.68% for Schottky -photodiode. Evaluated to in-plane MoS2 devices, the vertical design of these devices has a much larger junction area which is essential for achieving highly efficient photovoltaic devices. As well as spectral responsivity of 28.25 mA/W and 63.22 mA/W for Schottky and pn-photodiodes respectively also, response time of 1 ms for Schottky-photodiode and 977.5 μs for pn-photodiode were measured and discussed.