Structure And Mechanism Of Silicon Based Near Infrared Narrow-band Photodetectors

The near infrared narrow-band photodetectors are widely required in various applications,such as biological material identification and calibration,imaging in specific bands,military secret communication and optical system switch control for it can effectively enhance the anti-interference ability of system.The research on the device structure and mechanism of narrow-band detection has earned significant interest.Thanks to the pillar status of silicon in integrated circuit,the study of silicon-based photodetectors can effectively promote the development of optoelectronic integration in chips.Herein,two kinds of silicon-based narrow-band near-infrared photodetectors are constructed based on the controlling of light distribution in junction mechanism.The detection band of the photodetector can be modulated by adjusting the light distribution near depletion region in junction.The details are as follows:(1)We constructed narrow-band photodetector based on the Schottky junction of p-type silicon.The effects of barrier height and reflection coefficient of metal electrode on device performance are studied.High sensitive near infrared narrow-band photodetector were fabricated with Ti/Ag Schottky electrode.Its detection peak is around 1060 nm,and peak responsivity is 1.74 A/W with a FWHM(full width at half maximum)of about 74 nm at zero bias.What's more the linear dynamic range and detectivity of the device can be up to 128 d B and 4.14×10¹²Jones,respectively.Under the bias of-1 V,its external quantum efficiency can reach 1350%,with FWHM almost unchanged.The gain mechanism in the device should be due to the special device structure and the large difference between the transit time of electron and hole.(2)Near-infrared photodetectors were designed and fabricated based on MAPb I₃/Zn O/p-Si double junctions.The narrow-band photodetection of 1000-1100nm were realized by the two pn junctions,which can produce photocurrent with opposite direction under illumination,and the similar band gap of MAPb I₃and Si.The device can work under zero bias.And its sensitivity can be improved by applying bias voltage.The responsivity of the detector can reach 0.128 A/W at-1 V and 0.249 A/W at 1 V,respectively.