The optical responsivity of bulk-heterojunction field effect phototransistors (BH-FEpTs) based on poly [2-methoxy-5-(2´- ethylhexyloxy-p-phenylenevinylene)] (MEH-PPV) and PbS quantum dot hybrids is very low. A main reason for the low responsivity is the low carrier mobility of the blends. To overcome the shortcoming, graphene with high carrier mobility (~200,000 cm²V^-1s^-1) can be used for improving the responsivity of BH-FEpTs. However, the influence of monolayer graphene on the photo response of BH-FEpTs still has been not studied. In this papers, BH-FEpTs and GBH-FEpTs (single layer graphene beneath the BH layer in BH-FEpTs) were fabricated. Experimentally, the GBH-FEpTs showed ultrahigh mobility for both holes and electrons (μH and μE) of 183 and 169 cm²V⁻¹s⁻¹, while 11.3 and 6.2 cm²V⁻¹s⁻¹ in BH-FEpT. Due to the greatly promoted carrier mobility and highly ordered channels for GBH-FEpTs, higher α, μ and β are obtained for GBH-FEpTs. The responsivity of GBH-FEpTs is improved to 101 A/W, which is two orders magnitude larger than BH-FEpTs (10^-1 A/W).

Date Published: 31 October 2016
PDF: 11 pages
Proc. SPIE 10019, Optoelectronic Devices and Integration VI, 100190S (31 October 2016); doi: 10.1117/12.2242775

Published in SPIE Proceedings Vol. 10019:
Optoelectronic Devices and Integration VI
Xuping Zhang; Baojun Li; Changyuan Yu, Editor(s)