Airstable near-infrared sensitive organic field-effect transistors utilizing erbium phthalocyanine as photosensitive layer

Abstract

Near-infrared photosensitive organic field-effect transistors (PhOFETs) based on pentacene/erbium phthalocyanine (ErPc2) and copper phthalocyanine (CuPc)/ErPc2 heterojunction, as well as ErPc2 single-layer PhOFETs, were fabricated and characterized. The results showed that the heterojunction PhOFETs exhibit higher mobility, maximum photoresponsivity (Rmax) and maximum photo/dark current ratio (Pmax), comparing with the ErPc2 single-layer ones. Such a better performance of the heterojunction devices can be attributed to the higher mobility channel layer. And the pentacene/ErPc2 PhOFETs demonstrate an Rmax of 6498mA/W, Pmax of 2.6×103, hole mobility of 1.5×10−2cm2V−1s−1 and excellent air stability, its Rmax is 186 times larger than that of the ErPc2 single-layer PhOFETs. Therefore, ErPc2 can be used as an excellent NIR photoresponsive layer of heterojunction PhOFETs.