High-performance self-powered GaN/PEDOT:PSS hybrid heterojunction UV photodetector for optical communication

Self-powered ultraviolet photodetectors (UVPDs) provide great possibility for the next-generation energy conservation optical communication technology; while the high photodetection performance at zero bias is still a tremendous challenge. Herein, n-type GaN film with Si-doping concentration of similar to 1018 cm-3 and p-type organic PEDOT:PSS were adopted to construct a planar hybrid heterojunction via the simple spin-coating method. Profited from typical type-II energy band alignment and giant photovoltaic effect at GaN/PEDOT:PSS inorganic-organic interface, the fabricated UVPD achieved excellent self-powered photoelectrical properties in dual-band with large R of 0.96 A/W (2.8 A/W), superior D* of 5.7x1012 Jones (1.7x1013 Jones), prominent EQE of 325% (1371%), high on/off ratio of 9.65x103 (6.15x103) and fast rise/decay time of 60.7/124.5 ms (30.9/26.7 ms) for UVA (UVC) band, as well as outstanding UV/visible rejection ratio and great detection repeatability. Functioned as an optical signal receiver, this designed self-powered UVPD decoded a message of "NJUPT" from a simple optical communication system. These results open a new avenue for GaN/PEDOT:PSS heterojunction in UV communications and related applications.