A composite ultraviolet （UV）/blue photode- tector structure has been proposed, which is composed of P-type silicon substrate, Pwelb Nwell and N-channel metal- oxide-semiconductor field-effect transistor （NMOSFET） ...A composite ultraviolet （UV）/blue photode- tector structure has been proposed, which is composed of P-type silicon substrate, Pwelb Nwell and N-channel metal- oxide-semiconductor field-effect transistor （NMOSFET） realized in the PweH. In this photodetector, lateral ring- shaped Pwell-Nwell junction was used to separate the photogenerated carriers, and non-equilibrium excess hole was injected to the Pwell bulk for changing the bulk potential and shifting the NMOSFET＇s threshold voltage as well as the output drain current. By technology computer-aided design （TCAD） device, simulation and analysis of this proposed photodetector were carried out. Simulation results show that the combined photodetector has enhanced responsivity to UV/blue spectrum. More- over, it exhibits very high sensitivity to weak and especially ultral-weak optical light. A sensitivity of 7000 A/W was obtained when an incident optical power of 0.01 μW was illuminated to the photodetector, which is 35000 times higher than the responsivity of a conventional silicon-based UV photodiode （usually is about 0.2 A/W）. As a result, this proposed combined photodetector has great potential values for UV applications.展开更多
基金Acknowledgements This work was supported by the State Key Program of National Natural Science of China （Grant No. 61233010）, the National Natural Science Foundation of China （Grant No. 61274043）, and the Program for New Century Excellent Talents in University of Ministry of Education of China （NCET-11-0975）.
文摘A composite ultraviolet （UV）/blue photode- tector structure has been proposed, which is composed of P-type silicon substrate, Pwelb Nwell and N-channel metal- oxide-semiconductor field-effect transistor （NMOSFET） realized in the PweH. In this photodetector, lateral ring- shaped Pwell-Nwell junction was used to separate the photogenerated carriers, and non-equilibrium excess hole was injected to the Pwell bulk for changing the bulk potential and shifting the NMOSFET＇s threshold voltage as well as the output drain current. By technology computer-aided design （TCAD） device, simulation and analysis of this proposed photodetector were carried out. Simulation results show that the combined photodetector has enhanced responsivity to UV/blue spectrum. More- over, it exhibits very high sensitivity to weak and especially ultral-weak optical light. A sensitivity of 7000 A/W was obtained when an incident optical power of 0.01 μW was illuminated to the photodetector, which is 35000 times higher than the responsivity of a conventional silicon-based UV photodiode （usually is about 0.2 A/W）. As a result, this proposed combined photodetector has great potential values for UV applications.
