Enhanced ultraviolet photoresponse in a graphene-gated ultra-thin Sibased photodiode

Li, Guoli [UCL] André, Nicolas [UCL] Huet, Benjamin [UCL] Delhaye, Thibault [UCL] Reckinger, Nicolas [UCL] Francis, Laurent [UCL] Lioa, Lei [School of Physics and Electronics, Hunan University, Changsha, China] Raskin, Jean-Pierre [UCL] Zeng, Yun [School of Physics and Electronics, Hunan University, Changsha, China] Flandre, Denis [UCL] et al.[show all]

We present an ultra-thin lateral SOI PIN photodiode with transferred monolayer graphene as the transparent gate, to provide enhanced ultraviolet (UV) performance and mechanical flexibility beyond standard Si-based devices. The device dark current shows intact characteristics after the post-CMOS thinning and graphene transfer processing steps. The device responsivity presents high potential in UV and visible wavelength detections (i.e. within the 200–900nm range) under monochromatic light illumination. A maximum responsivity of 0.18 A W−1 has been experimentally achieved at 390nm wavelength and validated by simulation, for a diode with intrinsic length Li of 20 μm. Additionally, the ~5 μm-thick device chip with direct board assembly paves the way towards the development of hybrid flexible electronics.