The quest for solar-blind photodetectors with outstanding optoelectronic properties and weak signals detection capability is essential for their applications in the field of imaging,communication,warning,etc.To date,G...The quest for solar-blind photodetectors with outstanding optoelectronic properties and weak signals detection capability is essential for their applications in the field of imaging,communication,warning,etc.To date,Ga_(2)O_(3)has demonstrated potential for high-performance solar-blind photodetectors.However,the performance usually decays superlinearly at low light intensities due to carrier-trapping effect,which limits the weak signal detection capability of Ga_(2)O_(3)photodetectors.Herein,a Ga_(2)O_(3)solarblind photodetector with ultra-thin absorbing medium has been designed to restrain trapping of photo-generated carriers during the transporting process by shortening the carrier transport distance.Meanwhile,multiple-beam interference is employed to enhance the absorption efficiency of the Ga_(2)O_(3)layer using an Al/Al_(2)O_(3)/Ga_(2)O_(3)structure.Based on the ultra-thin absorbing medium with enhanced absorption efficiency,a 7×7 flexible photodetector array is developed,and the detectivity can reach 1.7×10^(15)Jones,which is among the best values ever reported for Ga_(2)O_(3)photodetectors.Notably,the performance of the photodetector decays little as the illumination intensity is as weak as 5 nW/cm2,revealing the capacity to detect ultra-weak signals.In addition,the flexible photodetector array can execute the functions of imaging,spatial distribution of light source intensity,real-time light trajectory detection,etc.Our results may provide a route to high-performance solar-blind photodetectors for ultra-weak light detection.展开更多
Objective] This study almed to compare the effects of three absorbing medium on microwave degradation of chIordane in contaminated soiI under alkaline condition. [Method] SoiI sampIes were coI ected from the original ...Objective] This study almed to compare the effects of three absorbing medium on microwave degradation of chIordane in contaminated soiI under alkaline condition. [Method] SoiI sampIes were coI ected from the original site of a reIocated pesticide production enterprise as experimental materials, to investigate the effects of Cu2O, MnO2 and activated carbon powder as absorbing medium on soiI warming and removal rate of chIordane under alkaline condition with 20% moisture content. In addition, the effects of activated carbon as the optimal absorbing media on the removal rate of chIordane in contaminated soiI were analyzed, and the effects on the removal rate of chIordane in different weights of soiI sampIes were investigated. [Result] The effects of three different absorbing medium on the removal rates of chIordane demonstrated a descending order of activated carbon ＆gt; MnO2 ＆gt; CuO2. Under the same microwave condition, the removal rate of chIordane decreased with the increase of soiI weights, but the utiIization efficiency of microwave was improved continuousIy and tended to be stabiIized with the increase of soiI weights. [Conclu-sion] This study provided a theoretical basis for further Iarge-scale appIication in soiI remediation.展开更多
An approximate analytic model is presented to describe spatial structure of refracted electromagnetic field arising at oblique incidence of a Gaussian beam on a plane boundary of an absorbing homogeneous medium. The a...An approximate analytic model is presented to describe spatial structure of refracted electromagnetic field arising at oblique incidence of a Gaussian beam on a plane boundary of an absorbing homogeneous medium. The analytic solution is obtained by asymptotic approximation of a Fourier field integral under the condition of great beam width in comparison with a wavelength (the geometrical-optics approximation). This model can be used also for approximate simulation of refracted field in the cases of beam incidence near the critical angle on transparent or absorbing (amplifying) refracting medium, if one artificially introduces the additional absorption (amplification), whose value is proportional to the ratio of the wavelength and the effective beam width. It is shown that the analytic model reflects the general features of refracted field at total internal reflection.展开更多
基金This work was financially supported by the National Key Research and Development Program of China(No.2018YFB0406500)the National Natural Science Foundation of China(Nos.61804136,U1804155,and 62027816)China Postdoctoral Science Foundation(Nos.2018M630829 and 2019T120630).
文摘The quest for solar-blind photodetectors with outstanding optoelectronic properties and weak signals detection capability is essential for their applications in the field of imaging,communication,warning,etc.To date,Ga_(2)O_(3)has demonstrated potential for high-performance solar-blind photodetectors.However,the performance usually decays superlinearly at low light intensities due to carrier-trapping effect,which limits the weak signal detection capability of Ga_(2)O_(3)photodetectors.Herein,a Ga_(2)O_(3)solarblind photodetector with ultra-thin absorbing medium has been designed to restrain trapping of photo-generated carriers during the transporting process by shortening the carrier transport distance.Meanwhile,multiple-beam interference is employed to enhance the absorption efficiency of the Ga_(2)O_(3)layer using an Al/Al_(2)O_(3)/Ga_(2)O_(3)structure.Based on the ultra-thin absorbing medium with enhanced absorption efficiency,a 7×7 flexible photodetector array is developed,and the detectivity can reach 1.7×10^(15)Jones,which is among the best values ever reported for Ga_(2)O_(3)photodetectors.Notably,the performance of the photodetector decays little as the illumination intensity is as weak as 5 nW/cm2,revealing the capacity to detect ultra-weak signals.In addition,the flexible photodetector array can execute the functions of imaging,spatial distribution of light source intensity,real-time light trajectory detection,etc.Our results may provide a route to high-performance solar-blind photodetectors for ultra-weak light detection.
基金Supported by Special Fund for the Transformation of Scientific and Technologica Achievements in Jiangsu Province(BA2013057)~~
文摘Objective] This study almed to compare the effects of three absorbing medium on microwave degradation of chIordane in contaminated soiI under alkaline condition. [Method] SoiI sampIes were coI ected from the original site of a reIocated pesticide production enterprise as experimental materials, to investigate the effects of Cu2O, MnO2 and activated carbon powder as absorbing medium on soiI warming and removal rate of chIordane under alkaline condition with 20% moisture content. In addition, the effects of activated carbon as the optimal absorbing media on the removal rate of chIordane in contaminated soiI were analyzed, and the effects on the removal rate of chIordane in different weights of soiI sampIes were investigated. [Result] The effects of three different absorbing medium on the removal rates of chIordane demonstrated a descending order of activated carbon ＆gt; MnO2 ＆gt; CuO2. Under the same microwave condition, the removal rate of chIordane decreased with the increase of soiI weights, but the utiIization efficiency of microwave was improved continuousIy and tended to be stabiIized with the increase of soiI weights. [Conclu-sion] This study provided a theoretical basis for further Iarge-scale appIication in soiI remediation.
文摘An approximate analytic model is presented to describe spatial structure of refracted electromagnetic field arising at oblique incidence of a Gaussian beam on a plane boundary of an absorbing homogeneous medium. The analytic solution is obtained by asymptotic approximation of a Fourier field integral under the condition of great beam width in comparison with a wavelength (the geometrical-optics approximation). This model can be used also for approximate simulation of refracted field in the cases of beam incidence near the critical angle on transparent or absorbing (amplifying) refracting medium, if one artificially introduces the additional absorption (amplification), whose value is proportional to the ratio of the wavelength and the effective beam width. It is shown that the analytic model reflects the general features of refracted field at total internal reflection.
