High performance Al/WSe2/CuO/ITO structure based broadband photodetector

This letter reports a Al/WSe2/CuO/ITO structure based broadband photodetector. The low cost spin coating technique is utilized to deposit, p-type WSe2 film and n-type CuO film. The Al contacts were deposited over WSe2 film using thermal evaporation unit. The suggested photodetector gives the broad photo response with maximum Responsivity RS (A/W) and External Quantum Efficiency (EQE) value of 3099 A/W, 3680 A/W, and 493 A/W; 1.20 x 106%, 1.52x 106% and 2.04 x 105% at 350 nm (UV), 500 nm (visible) and 950 nm (IR) under application of -2 V bias. The EQE value beyond 100% are attributed to trap assisted photomultiplication mechanism.