We analyzed the characteristics of cross-modulations (XM) and their recovery times in a semiconductor optical amplifier by a newly-developed TMM. The calculated results suggest faster recovery of the XMs by introducin...We analyzed the characteristics of cross-modulations (XM) and their recovery times in a semiconductor optical amplifier by a newly-developed TMM. The calculated results suggest faster recovery of the XMs by introducing a high-power assist light.展开更多
Based on two-dimensional(2D)semiconductor Bloch equation simulations,we demonstrate tunable high-order harmonic generation in monolayer MoS_(2) driven by counter-rotating two-color circular laser pulses.Single-helicit...Based on two-dimensional(2D)semiconductor Bloch equation simulations,we demonstrate tunable high-order harmonic generation in monolayer MoS_(2) driven by counter-rotating two-color circular laser pulses.Single-helicity harmonic generation is achievable:tuning the fundamental-to-second-harmonic field amplitude ratio suppresses left-handed plateau harmonics,yielding dominant right-handed emission.Valley-resolved analysis attributes this to destructive interference between K/K′-valley harmonics along both x and y axes.Further adjustment of the amplitude ratio and field rotation angle reverses the helicity,switching to left-handed dominance and enabling on-demand helicity control.This work deciphers the valley-interference mechanism governing circular harmonic generation in 2D transition-metal dichalcogenides,pioneering a pathway to single-helicity harmonics and solidstate circular attosecond pulses.展开更多
Metal halide perovskites(MHPs)have demonstrated excellent performances in detection of X-rays and gamma-rays.Most studies focus on improving the sensitivity of single-pixel MHP detectors.However,little work pays atten...Metal halide perovskites(MHPs)have demonstrated excellent performances in detection of X-rays and gamma-rays.Most studies focus on improving the sensitivity of single-pixel MHP detectors.However,little work pays attention to the dark current,which is crucial for the back-end circuit integration.Herein,the requirement of dark current is quantitatively evaluated as low as 10^(−9)A/cm^(2)for X-ray imagers integrated on pixel circuits.Moreover,through the semiconductor device analysis and simulation,we reveal that the main current compositions of thick perovskite X-ray detectors are the thermionic-emission current(J_(T))and the generation-recombination current(J_(g-r)).The typical observed failures of p-n junctions in thick detectors are caused by the high generation-recombination current due to the band mismatch and interface defects.This work provides a deep insight into the design of high sensitivity and low dark current perovskite X-ray detectors.展开更多
文摘We analyzed the characteristics of cross-modulations (XM) and their recovery times in a semiconductor optical amplifier by a newly-developed TMM. The calculated results suggest faster recovery of the XMs by introducing a high-power assist light.
基金supported by the National Natural Science Foundation of China(Grant Nos.12374029,62474154,and 12304278)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LY23A040001)the Natural Science Foundation of Shandong Province(Grant No.ZR2023QA127)。
文摘Based on two-dimensional(2D)semiconductor Bloch equation simulations,we demonstrate tunable high-order harmonic generation in monolayer MoS_(2) driven by counter-rotating two-color circular laser pulses.Single-helicity harmonic generation is achievable:tuning the fundamental-to-second-harmonic field amplitude ratio suppresses left-handed plateau harmonics,yielding dominant right-handed emission.Valley-resolved analysis attributes this to destructive interference between K/K′-valley harmonics along both x and y axes.Further adjustment of the amplitude ratio and field rotation angle reverses the helicity,switching to left-handed dominance and enabling on-demand helicity control.This work deciphers the valley-interference mechanism governing circular harmonic generation in 2D transition-metal dichalcogenides,pioneering a pathway to single-helicity harmonics and solidstate circular attosecond pulses.
基金supported by the Major State Basic Research Development Program of China(No.2021YFB3201000)the National Natural Science Foundation of China(Grant Nos.62074066,62134003,and 12050005)+2 种基金the Fund for Innovative Research Groups of the Natural Science Foundation of Hubei Province(Nos.2021CFA036 and 2020CFA034)Shenzhen Basic Research Program(No.JCYJ20200109115212546)the Fundamental Research Funds for the Central Universities.
文摘Metal halide perovskites(MHPs)have demonstrated excellent performances in detection of X-rays and gamma-rays.Most studies focus on improving the sensitivity of single-pixel MHP detectors.However,little work pays attention to the dark current,which is crucial for the back-end circuit integration.Herein,the requirement of dark current is quantitatively evaluated as low as 10^(−9)A/cm^(2)for X-ray imagers integrated on pixel circuits.Moreover,through the semiconductor device analysis and simulation,we reveal that the main current compositions of thick perovskite X-ray detectors are the thermionic-emission current(J_(T))and the generation-recombination current(J_(g-r)).The typical observed failures of p-n junctions in thick detectors are caused by the high generation-recombination current due to the band mismatch and interface defects.This work provides a deep insight into the design of high sensitivity and low dark current perovskite X-ray detectors.
