The slower response speed is the main problem in the application of ZnO quantum dots(QDs)photodetector,which has been commonly attributed to the presence of excess oxygen vacancy defects and oxygen adsorption/desorpti...The slower response speed is the main problem in the application of ZnO quantum dots(QDs)photodetector,which has been commonly attributed to the presence of excess oxygen vacancy defects and oxygen adsorption/desorption processes.However,the detailed mechanism is still not very clear.Herein,the properties of ZnO QDs and their photodetectors with different amounts of oxygen vacancy(VO)defects controlled by hydrogen peroxide(H_(2)O_(2))solution treatment have been investigated.After H_(2)O_(2) solution treatment,VO concentration of ZnO QDs decreased.The H_(2)O_(2) solution-treated device has a higher photocurrent and a lower dark current.Meanwhile,with the increase in VO concentration of ZnO QDs,the response speed of the device has been improved due to the increase of oxygen adsorption/desorption rate.More interestingly,the response speed of the device became less sensitive to temperature and oxygen concentration with the increase of VO defects.The findings in this work clarify that the surface VO defects of ZnO QDs could enhance the photoresponse speed,which is helpful for sensor designing.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.62074148,61875194,11727902,12074372,11774341,11974344,61975204,and 11804335)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2020225)the Open Project of the State Key Laboratory of Luminescence and Applications(Grant Nos.SKLA-2020-02 and SKLA-2020-06).
文摘The slower response speed is the main problem in the application of ZnO quantum dots(QDs)photodetector,which has been commonly attributed to the presence of excess oxygen vacancy defects and oxygen adsorption/desorption processes.However,the detailed mechanism is still not very clear.Herein,the properties of ZnO QDs and their photodetectors with different amounts of oxygen vacancy(VO)defects controlled by hydrogen peroxide(H_(2)O_(2))solution treatment have been investigated.After H_(2)O_(2) solution treatment,VO concentration of ZnO QDs decreased.The H_(2)O_(2) solution-treated device has a higher photocurrent and a lower dark current.Meanwhile,with the increase in VO concentration of ZnO QDs,the response speed of the device has been improved due to the increase of oxygen adsorption/desorption rate.More interestingly,the response speed of the device became less sensitive to temperature and oxygen concentration with the increase of VO defects.The findings in this work clarify that the surface VO defects of ZnO QDs could enhance the photoresponse speed,which is helpful for sensor designing.
