Li Wang, Hehao Luo, Huanhuan Zuo, Jiqing Tao, Yongqiang Yu, Xiaoping Yang, Molin Wang, Jigang Hu,* Chao Xie,

Di Wu and Linbao Luo*

Abstract:Photodetection at wavelength of about 1060 nm is very important for applications including medical imaging, optical communication, and light detection and ranging. In this work, a self-powered near infrared light detector with a narrowband at around 1060 nm is realized based on a simple Si Schottky structure, in which the Ohmic and Schottky electrodes are configured on the front and rear surfaces of Si substrate, respectively. The as-assembled device exhibits a tunable peak response near 1060 nm with a full width at half maximum of 107 nm, which could be due to the combined effect of the narrow photo-current generation and the self-filtering effect of silicon substrate. At zero bias, a specific detectivity of ~1×10¹¹Jones and linear dynamic range about 101 dB are achieved, in spite of the weak absorption of Si at this wavelength. The external quantum efficiency can be improved to 135% under a low bias of -1V, indicating the existence of gain mechanism during photodetection. Finally, it is also found that the as-assembled near infrared device shows excellent anti-interference capability during photodetection process. These results corroborate that the present Si photodetector may find promising application in future near infrared optoelectronic devices and systems.