A highly efficient bilayer graphene/ZnO/silicon nanowire based heterojunction photodetector with broadband spectral response
Shonak Bansal, Krishna Prakash, Kuldeep Sharma, Neha Sardana, Sanjeev Kumar, Neena Gupta, Arun Kumar Singh
Abstract
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 × 10 12 cmHz 1/2 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.