Abstract:
This paper presents three self-powered photodetectors namely, p+-bilayer graphene
(BLG)/n+-ZnO nanowires (NWs), p+-BLG/n+-Si NWs/p–-Si and p+-BLG/n+-ZnO
NWs/p–-Si. The Silvaco Atlas TCAD software is utilized to characterize the optoelectronic
properties of all the devices and is validated by analytical modeling. The proposed dual-junction
photodetectors cover broadband spectral response varying from ultraviolet to near-infrared
wavelengths. The dual-heterojunction broadband photodetector exhibits photocurrent switching
with the rise and fall time of 1.48 and 1.27 ns, respectively. At −0.5 V bias, the highest external
quantum efficiency, photocurrent responsivity, specific detectivity, and the lowest noise
equivalent power of 71%, 0.28 A W−1, 4.2 × 1012 cmHz1/2 W−1, and 2.59 × 10–17 W,
respectively, are found for the dual-heterojunction device with a wavelength of 480 nm at
300 K. The proposed nanowires based photodetectors offer great potential to be utilized as
next-generation optoelectronic devices.
