Broadband MoS2 Field-Effect Phototransistors Ultrasensitive Visible-Light Photoresponse and Negative Infrared Photoresponse

Broadband MoS2 Field-Effect Phototransistors : Ultrasensitive Visible-Light Photoresponse and Negative Infrared Photoresponse

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bibliographische Detailangaben
Veröffentlicht in:Advanced materials (Deerfield Beach, Fla.). - 1998. - 30(2018), 7 vom: 20. Feb.
1. Verfasser: Wu, Jing-Yuan (VerfasserIn)
Weitere Verfasser: Chun, Young Tea, Li, Shunpu, Zhang, Tong, Wang, Junzhan, Shrestha, Pawan Kumar, Chu, Daping
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2018
Zugriff auf das übergeordnete Werk:Advanced materials (Deerfield Beach, Fla.)
Schlagworte:Journal Article bolometric effect inverse photoresponse molybdenum disulfide sub-bandgap photodetector ultrahigh photoresponsivity
Beschreibung
Zusammenfassung:© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Inverse photoresponse is discovered from phototransistors based on molybdenum disulfide (MoS2 ). The devices are capable of detecting photons with energy below the bandgap of MoS2 . Under the illumination of near-infrared (NIR) light at 980 and 1550 nm, negative photoresponses with short response time (50 ms) are observed for the first time. Upon visible-light illumination, the phototransistors exhibit positive photoresponse with ultrahigh responsivity on the order of 104 -105 A W-1 owing to the photogating effect and charge trapping mechanism. Besides, the phototransistors can detect a weak visible-light signal with effective optical power as low as 17 picowatts (pW). A thermally induced photoresponse mechanism, the bolometric effect, is proposed as the cause of the negative photocurrent in the NIR regime. The thermal energy of the NIR radiation is transferred to the MoS2 crystal lattice, inducing lattice heating and resistance increase. This model is experimentally confirmed by low-temperature electrical measurements. The bolometric coefficient calculated from the measured transport current change with temperature is -33 nA K-1 . These findings offer a new approach to develop sub-bandgap photodetectors and other novel optoelectronic devices based on 2D layered materials
Beschreibung:Date Completed 01.08.2018
Date Revised 30.09.2020
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.201705880