title: Comparison of photoresponse of transistors based on graphene-quantum dot hybrids with layered and bulk heterojunctions.
abstract: Phototransistors based on graphene-quantum dot hybrids have a high responsivity and gain. However, the influence of the type of heterojunction on the photoresponse of the transistors is still undetermined. A comparison was performed on field-effect phototransistors (FEpTs) with two types of heterojunctions: layered heterojunctions (LHs) and bulk heterojunctions (BHs). Through a comparative study, it was shown that BH-FEpTs had electron and hole mobilities (μE and μH) of 677 and 527 cm(2) V(-1) s(-1) whereas LH-FEpTs had lower mobilities of μE = 314 cm(2) V(-1) s(-1) and μH = 367 cm(2) V(-1) s(-1). The large interfacial area in the BHs reduced the degree of channel order (α) by two orders of magnitude compared with the LHs. Although a higher mobility was achieved, an increase in the degree of channel disorder and the lack of an effective transfer mechanism limits the responsivity in BH-FEpTs. Therefore, LH-FEpTs are more appropriate candidates for near infrared phototransistors.
authors.affiliation: Institute of Laser & Opto-Electronics, College of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072, People's Republic of China. Key Laboratory of Opto-electronics Information Technology (Tianjin University), Ministry of Education, Tianjin 300072, People's Republic of China.
authors.forename: Yating
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaoxian
authors.initials: X
authors.lastname: Song
authors.forename: Ran
authors.initials: R
authors.lastname: Wang
authors.forename: Mingxuan
authors.initials: M
authors.lastname: Cao
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.forename: Yongli
authors.initials: Y
authors.lastname: Che
authors.forename: Xin
authors.initials: X
authors.lastname: Ding
authors.forename: Jianquan
authors.initials: J
authors.lastname: Yao