MoS2, rGO, and CuO Nanocomposite-Based High Performance UV-Visible Dual-Band Photodetectors

Abstract

This letter reports a Pd/MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /rGO/CuO/ITO structure based Metal-Semiconductor-Metal (MSM) photodetector. The proposed MSM device is obtained by vertical integration of a Pd/MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Schottky junction and a CuO /ITO (i.e., (Indium-doped Tin Oxide) Schottky junction separated by thin reduced graphene oxide (rGO) layer. The rGO layer is used to improve the quality of the MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> layer by mitigating the effects of both the lattice mismatching and van der Waals gap between the MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (Molybdenum disulphide) and CuO (Copper Oxide) layer. The proposed photodetector shows a UV-Visible dual-band photoresponse when the device is illuminated by a monochromatic light intensity of 13.6μ W/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at different wavelengths over 300-800 nm. Excellent responsivities and detectivities of 646.8 A/W and 7.28 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14</sup> Jones at ~300 nm (in the UV region) and; of 84.32 A/W and 9.6 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> Jones at ~498 nm (in the visible region) are measured at 1 V bias voltage, respectively. Also, the device also shows exceptionally high external quantum efficiency (EQE) of 2.6 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> % and 3.7 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> % at 300 nm and 498 nm, respectively.