Abstract
Due to the wide range of potential applications for next-generation multi-functional devices,the flexible self-powered photodetector(PD)with polarity-switchable behavior is essential but very challenging to be realized.Herein,a wearable bidirectional self-powered PD based on detached(Al,Ga)N and(In,Ga)N nanowires has been proposed and demonstrated successfully.Arising from the photo voltage-competing dynamics across(Al,Ga)N and(In,Ga)N nanowire photoelectrodes,such PD can generate the positive(33.3 mA W-1)and negative(-0.019 mA W-1)photo-responsivity under ultraviolet(UV)and visible illumination,respectively,leading to the bidirectional photocurrent behavior.Thanks to the introduction of quasi solid-state hydrogel,the PD can work without the liquid-electrolyte,thus remarkably reducing the volume from about 482 cm3 to only 0.18 cm3.Furthermore,the use of hydrogel is found to enhance response speed in the UV range by reducing the response time for more than 95％,which is mainly attributed to the increased open circuit potential and reduced ion transport distance.As the GaN connecting segment is pretty thin,the piezoelectric charges generated by stress are proposed to have only a limited effect on the photocurrent density.Therefore,both the stable on-off switching characteristics and photocurrent densities can still be achieved after being bent 400 times.With an excellent flexibility,this work creates opportunities for technological applications of bidirectional photocurrent PDs in flexible optoelectronic devices,e.g.,wearable intelligent sensors.
基金项目
国家自然科学基金(62174172)
国家自然科学基金(61875224)
国家自然科学基金(61827823)
Key Research and Development Program of Jiangsu Province(BE2018005)
中国科学院前沿科学重点研究计划(ZDBS-LY-JSC034)
江西省自然科学基金(20192BBEL50033)
Research Program of Scientific Instrument and Equipment of CAS(YJKYYQ20200073)
SINANO(Y8AAQ21001)
Vacuum Interconnected Nanotech Workstation(Nano-X)(F2201)
Platform for Characterization & Test of SINANO,CAS()
NETL
NSTL
万方数据