The influence of the virtual guard ring width(GRW)on the performance of the p-well/deep n-well single-photon avalanche diode(SPAD)in a 180 nm standard CMOS process was investigated.TCAD simulation demonstrates that th...The influence of the virtual guard ring width(GRW)on the performance of the p-well/deep n-well single-photon avalanche diode(SPAD)in a 180 nm standard CMOS process was investigated.TCAD simulation demonstrates that the electric field strength and current density in the guard ring are obviously enhanced when GRW is decreased to 1μm.It is experimentally found that,compared with an SPAD with GRW=2μm,the dark count rate(DCR)and afterpulsing probability(AP)of the SPAD with GRW=1μm is significantly increased by 2.7 times and twofold,respectively,meanwhile,its photon detection probability(PDP)is saturated and hard to be promoted at over 2 V excess bias voltage.Although the fill factor(FF)can be enlarged by reducing GRW,the dark noise of devices is negatively affected due to the enhanced trap-assisted tunneling(TAT)effect in the 1μm guard ring region.By comparison,the SPAD with GRW=2μm can achieve a better trade-off between the FF and noise performance.Our study provides a design guideline for guard rings to realize a low-noise SPAD for large-array applications.展开更多
A patterned polymer dispersed liquid crystal transparent display using one-time UV exposure is demonstrated.The device is fabricated by exposing the cell with a uniform UV light through a mask with selective attenuati...A patterned polymer dispersed liquid crystal transparent display using one-time UV exposure is demonstrated.The device is fabricated by exposing the cell with a uniform UV light through a mask with selective attenuation of the UV light.The voltage-transmittance response of the device is different for the corresponding regions.Thus,three different states of total scattering,patterned transparent,and total transparent can be realized by controlling the applied voltages.The proposed device used in shutter mode as smart windows and in projected display mode is demonstrated,which shows great potential for smart windows with customized patterns or logos and has potential application in the field of projected transparent displays.展开更多
A tunable stepped-impedance resonator using liquid crystal is demonstrated.Two resonant frequencies at 3.367 and 7.198 GHz are realized and can be continuously tuned by external applied voltages.Continuous tunable ran...A tunable stepped-impedance resonator using liquid crystal is demonstrated.Two resonant frequencies at 3.367 and 7.198 GHz are realized and can be continuously tuned by external applied voltages.Continuous tunable ranges of 52 and 210 MHz have been achieved at a particularly low driving voltage of 14 V,which shows good agreement with the simulation results.The voltage-induced hysteresis phenomenon is also investigated.This device also has a low insertion loss of-2.9 and-4 dB for the two resonant frequencies and the return losses are less than-21.5 dB.This work provides a new protocol to realize a tunable frequency for communication systems.展开更多
基金supported by the Jiangsu Agricultural Science and Technology Innovation Fund of China(No.CX(21)3062)the National Natural Science Foundation of China(No.62171233).
文摘The influence of the virtual guard ring width(GRW)on the performance of the p-well/deep n-well single-photon avalanche diode(SPAD)in a 180 nm standard CMOS process was investigated.TCAD simulation demonstrates that the electric field strength and current density in the guard ring are obviously enhanced when GRW is decreased to 1μm.It is experimentally found that,compared with an SPAD with GRW=2μm,the dark count rate(DCR)and afterpulsing probability(AP)of the SPAD with GRW=1μm is significantly increased by 2.7 times and twofold,respectively,meanwhile,its photon detection probability(PDP)is saturated and hard to be promoted at over 2 V excess bias voltage.Although the fill factor(FF)can be enlarged by reducing GRW,the dark noise of devices is negatively affected due to the enhanced trap-assisted tunneling(TAT)effect in the 1μm guard ring region.By comparison,the SPAD with GRW=2μm can achieve a better trade-off between the FF and noise performance.Our study provides a design guideline for guard rings to realize a low-noise SPAD for large-array applications.
基金supported by the National Natural Science Foundation of China (Nos. 11904177 and 61704090)the Natural Science Foundation of Jiangsu Province (Nos. BK20170908 and BK20170903)
文摘A patterned polymer dispersed liquid crystal transparent display using one-time UV exposure is demonstrated.The device is fabricated by exposing the cell with a uniform UV light through a mask with selective attenuation of the UV light.The voltage-transmittance response of the device is different for the corresponding regions.Thus,three different states of total scattering,patterned transparent,and total transparent can be realized by controlling the applied voltages.The proposed device used in shutter mode as smart windows and in projected display mode is demonstrated,which shows great potential for smart windows with customized patterns or logos and has potential application in the field of projected transparent displays.
基金the National Natural Science Foundation of China(Nos.61704090 and 11904177)the Natural Science Foundation of Jiangsu Province,China(Nos.BK20170908 and BK20170903)+2 种基金the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province,China(No.17KJA470005)the National and Local Joint Engineering Laboratory of RF Integration and Micro-Assembly Technology(No.KFJJ20180201)NUPTSF(Nos.NY217123 and NY217124)。
文摘A tunable stepped-impedance resonator using liquid crystal is demonstrated.Two resonant frequencies at 3.367 and 7.198 GHz are realized and can be continuously tuned by external applied voltages.Continuous tunable ranges of 52 and 210 MHz have been achieved at a particularly low driving voltage of 14 V,which shows good agreement with the simulation results.The voltage-induced hysteresis phenomenon is also investigated.This device also has a low insertion loss of-2.9 and-4 dB for the two resonant frequencies and the return losses are less than-21.5 dB.This work provides a new protocol to realize a tunable frequency for communication systems.
