Suitable bandgap,high solar-blind light sensitivity,and high stability against harsh environments make Ga_(2)O_(3) a promising candidate in the application of solar-blind photodetectors.However,Ga_(2)O_(3) photodetect...Suitable bandgap,high solar-blind light sensitivity,and high stability against harsh environments make Ga_(2)O_(3) a promising candidate in the application of solar-blind photodetectors.However,Ga_(2)O_(3) photodetectors,particularly those dominated by the photoconductive effect,inevitably face a trade-off between photoresponsivity and response speed.Common methods to mitigate this trade-off usually improve one aspect with the compromise of another.In this work,bilayer-structure Ga_(2)O_(3) films are adopted for solar-blind photodetectors to alleviate the trade-off of photoresponsivity and response speed.The performance improvement effect of the bilayer-structure device is credited to its favorable modulation of carrier redistribution between two layers and extraction accessibility by the electrode.Through further optimization of film crystallinity by annealing,the bilayer-structure device acquires improved photoresponse performance,including a low dark current of 1.16 pA,a high photo to dark current ratio of 3.49×^(5),a high R of 236.10 A W^(–1),a high rejection ratio(R_(254nm)/R_(365nm))of 1.98×10^(5),and a fast decay speed of 50 ms.Such excellent comprehensive performance ranks it into the top level among similar Ga_(2)O_(3) photodetectors dominated by the photoconductive effect.This work provides a universal and facile design to mitigate the trade-off between photoresponsivity and response speed of Ga_(2)O_(3) solar-blind photodetectors.展开更多
基金National Key Research and Development Program of China Stem Cell and Translational Research,Grant/Award Numbers:2023YFB3610200,2024YFA120880,2024YFB3212200National Natural Science Foundation of China,Grant/Award Numbers:62474169,61925110,U20A20207,62304215Funding support from University of Science and Technology of China(USTC),Grant/Award Numbers:WK2100000025,KY2190000003,KY2190000006,YD2100002009。
文摘Suitable bandgap,high solar-blind light sensitivity,and high stability against harsh environments make Ga_(2)O_(3) a promising candidate in the application of solar-blind photodetectors.However,Ga_(2)O_(3) photodetectors,particularly those dominated by the photoconductive effect,inevitably face a trade-off between photoresponsivity and response speed.Common methods to mitigate this trade-off usually improve one aspect with the compromise of another.In this work,bilayer-structure Ga_(2)O_(3) films are adopted for solar-blind photodetectors to alleviate the trade-off of photoresponsivity and response speed.The performance improvement effect of the bilayer-structure device is credited to its favorable modulation of carrier redistribution between two layers and extraction accessibility by the electrode.Through further optimization of film crystallinity by annealing,the bilayer-structure device acquires improved photoresponse performance,including a low dark current of 1.16 pA,a high photo to dark current ratio of 3.49×^(5),a high R of 236.10 A W^(–1),a high rejection ratio(R_(254nm)/R_(365nm))of 1.98×10^(5),and a fast decay speed of 50 ms.Such excellent comprehensive performance ranks it into the top level among similar Ga_(2)O_(3) photodetectors dominated by the photoconductive effect.This work provides a universal and facile design to mitigate the trade-off between photoresponsivity and response speed of Ga_(2)O_(3) solar-blind photodetectors.
