High Performance Er doped ZnO(EZO)/WSe₂ Heterostructure based Wideband Photodetector

This article reports Al/Erbium doped ZnO/WSe2/ITO coated PET structure based wideband photodetector. The EZO and WSe ₂ are deposited using spin coating method, whereas, Al contacts were deposited over EZO layer using thermal evaporation technique. The p-type tungsten di-selenide (WSe ₂ ) layer deposited over Indium Tin Oxide (ITO) coated Polyethylene terephthalate (PET) substrate forms a heterojunction with n-type Erbium doped ZnO (EZO) layer. The photodetector performance parameters like responsivity, external quantum efficiency (EQE), specific detectivity and sensitivity were calculated at fixed power of 0.118 μw and at 2Vbias. The proposed device shows a very high External Quantum Efficiency (EQEs)/Responsivity R_s (A/W) of 2.26× 10 ⁴ % / 72.90,6.3×10 ³ %/ 30.60 ,1.52×10 ³ % / 14.10 at 400nm (UV),600nm (Visible) and 1150nm (NIR) respectively, under 2Vbias. Further, the proposed photodetector behaves as a self-powered detector for normal as well as circularly polarized light. The proposed photodetector may find its application in optoelectronics for broadband detection and polarization sensors.