Highly responsive graphene phototransistor for visible light enhanced by poly(3-hexylthiophene)

A low-cost phototransistor using poly(3-hexylthiophene) (P3HT) and a graphene hybrid channel was fabricated by a solution-processing method, which exhibited excellent optoelectronic properties due to the combination of superior light absorption of P3HT and high charge mobility of graphene. The phototransistor exhibited a high hole mobility of up to 18 cm2 V−1 s−1. The device showed a sensitive and stable response in the visible light range with a responsivity (R) of 18 A/W and a short rise/decay response time of 2.2/2.3 ms. These excellent performances were benefited from the fast carrier transfer from P3HT to graphene and the high mobility of graphene. The P3HT-graphene hybrid phototransistor provides an excellent opportunity for developing high performance optoelectronic devices.