Ytterbium doping reduces the dark current of UV photoelectric detector based on TiO2

Abstract

Improved performance of TiO2-based UV photodetectors needs functional improvements in materials. Doping can modulate the electron and hole concentration and band structure of materials. This work shows that doping Yb into TiO2 improves the performance of TiO2-based UV photodetectors. It is found experimentally that doping Yb can cause Yb ions to replace Ti ions in lattice of TiO2, which is conducive to adjusting the physical and chemical properties from the perspective of energy band engineering. The dark current of the detector was less than 1 nA at bias of 5 V. Under UV radiation, the device achieved a maximum switching rate of 3.64 ⅹ 103 when the doping concentration of Yb was 5%, and the recovery time dropped from 1.4 s to 0.65 s.