In the past, benefiting from the mature micro-technologies of crystalline-silicon (c-Si), c-Si electronic and optoelectronic devices have brought revolutionary convenience to daily lives, with sensitive visible and near-infrared photodetectors, the basic device in cameras for visible spectroscopy and color imaging, as an example. However, the sensitivity of all-Si photodetectors cannot meet the needs of deep-ultraviolet (DUV) detection with important applications in spectral imaging analysis. Based on this circumstance, a 0D-3D silicon-integrated photodiode is presented to obtain highly sensitive DUV detection. A vertically stacked graphene/GAO/Si back-to-back photodiode has high photoresponsivity (0.165 A/W and EQE approximate to 80.2% at 0 V bias, 7.42 A/W and EQE approximate to 3611% at -1 V bias) and fast response speed (3 ms) under DUV illumination by using composite modified wide-band-gap oxide colloidal quantum dots as the DUV sensitive layer. The performance of the detector is successfully verified by DUV imaging with a single-point-detection imaging system.

colloidal quantum dots; ligand tailoring; oxides; Si-integrated photodiodes; ultraviolet radiation

Sun Yat-sen University