Oxygen vacancies modulating self-powered photoresponse in PEDOT:PSS/ε-Ga_(2)O_(3)heterojunction by trapping effect

Can the modulation effect of charge-carrier transfer be inherited from a single layer to its heterojunction structure?Certainly,the answer is yes.Herein,we experimentally verify that the photodetection performance modulation effect of oxygen vacancy(Vo)is transmitted from theε-Ga_(2)O_(3)layer to the PEDOT:PSS/ε-Ga_(2)O_(3)(PGO)hybrid heterojunction.By adopting the annealedε-Ga_(2)O_(3)films,whose Voconcentrations are remolded by annealing ambients,the constructed PGO photodetectors(PDs)demonstrate regulable self-powered performance.As the V_(o)defects decrease,the photodetection properties are effectively enhanced with a high photo-to-dark current ratio of 2.37×10^(7),an excellent on/off switching ratio of 6.45×10^(5),fast rise/decay time of 121/72 ms,a large responsivity of 67.9 m A/W,superior detectivity of 9.2×10^(13)Jones,an outstanding external quantum efficiency of 33.2%,and a high rejection ratio(R_(250)/R_(400))of 5.96×10^(6)at 0 V in PGO-O;PD.The better photoresponse is attributed to the less V_(o)defect concentration in theε-Ga_(2)O_(3)layer,which could favor the lower electron-trapping probability and a more efficient charge-carrier transfer.Considering the universality of V_(o)defects in oxide materials,the proposed regulation strategy of photoresponse will open the route of high self-powered performance for next-generation ultraviolet PDs.