High performance rigid and flexible visible-light photodetectors based on aligned X(In, Ga)P nanowire arrays

InP and GaP nanowires (NWs) were synthesized via a simple thermal evaporation method for applications as high performance visible-light photodetectors. Individual InP NW field-effect transistors (FETs) were fabricated to study their electronic transport and photoresponse characteristics, which exhibited typical n-type transistor characteristics with an efficient electron mobility of 1.21 cm² V^-1 s ^-1, a fast response time (∼0.1 s) and good sensitivity with a spectral responsivity of 779.14 A W^-1 and a high quantum efficiency of 1.53 × 10⁵% to visible light irradiation. Using the contact printing process, large scale aligned InP NW arrays were assembled on both rigid SiO₂/Si and flexible PET substrates. Both rigid and flexible InP NW array based photodetectors demonstrated excellent photoresponse performance, especially a faster response, for example, from 0.1 s to 80 ms. In addition, the flexible InP NW array based photodetectors exhibited good flexibility, good folding endurance and electrical stability. Using similar processes, aligned GaP NW array based photodetectors were also fabricated on SiO₂/Si and PET substrates, which also exhibited fast, reversible, and stable photoresponse properties. These merits demonstrate that the as-prepared InP and GaP NWs are good candidates with substantial potential for future electronic and optoelectronic nanodevice applications.