Surface plasmon assisted high-performance photodetectors based on hybrid TiO2@GaOxNy-Ag heterostructure

In this work,we reported a high-performance-based ultraviolet-visible(UV-VIS)photodetector based on a TiO2@GaOxNy-Ag heterostructure.Ag particles were introduced into TiO2@GaOxNy to enhance the visible light detection perfor-mance of the heterojunction device.At 380 nm,the responsivity and detectivity of TiO2@GaOxNy-Ag were 0.94 A/W and 4.79×109 Jones,respectively,and they increased to 2.86 A/W and 7.96×1010 Jones at 580 nm.The rise and fall times of the response were 0.19/0.23 and 0.50/0.57 s,respectively.Uniquely,at 580 nm,the responsivity of fabricated devices is one to four orders of magnitude higher than that of the photodetectors based on TiO2,Ga2O3,and other heterojunctions.The excellent optoelectronic characteristics of the TiO2@GaOxNy-Ag heterojunction device could be mainly attributed to the synergistic effect of the type-Ⅱ band structure of the metal-semiconductor-metal heterojunction and the plasmon resonance effect of Ag,which not only effectively promotes the separation of photogenerated carriers but also reduces the recombination rate.It is fur-ther illuminated by finite difference time domain method(FDTD)simulation and photoelectric measurements.The TiO2@GaOxNy-Ag arrays with high-efficiency detection are suitable candidates for applications in energy-saving communica-tion,imaging,and sensing networks.