Negative Photoresponse Switching via Electron-Hole Recombination at The Type III Junction of MoTe2 Channel/SnS2 Top Layer

© 2023 Wiley-VCH GmbH.

Détails bibliographiques
Publié dans:Advanced materials (Deerfield Beach, Fla.). - 1998. - 35(2023), 48 vom: 01. Nov., Seite e2304599
Auteur principal: Jeong, Yeonsu (Auteur)
Autres auteurs: Kim, Taewook, Cho, Hyunmin, Ahn, Jongtae, Hong, Sungjae, Hwang, Do Kyung, Im, Seongil
Format: Article en ligne
Langue:English
Publié: 2023
Accès à la collection:Advanced materials (Deerfield Beach, Fla.)
Sujets:Journal Article SnS2/MoTe2 e-h recombination negative photoresponsivity photo-FET type III junction
Description
Résumé:© 2023 Wiley-VCH GmbH.
Extensive study on 2D van der Waals (vdW) heterojunctions has primarily focused on PN diodes for fast-switching photodetection, while achieving the same from 2D channel phototransistors is rare despite their other advantages. Here, a high-speed phototransistor featuring a type III junction between p-MoTe2 channel and n-SnS2 top layer is designed. The photodetecting device operates with a basis of negative photoresponse (NPR), which originates from the recombination of photoexcited electrons in n-SnS2 and accumulated holes in the p-MoTe2 channel. For the NPR to occur, high-energy photons capable of exciting SnS2 (band gap ≈2.2 eV) are found to be effective because lower-energy photons simply penetrate the SnS2 top layer only to excite MoTe2 , leading to normal positive photoresponse (PPR) which is known to be slow due to the photogating effects. The NPR transistor showcases 0.5 ms fast photoresponses and a high responsivity over 5000 A W-1 . More essentially, such carrier recombination mechanism is clarified with three experimental evidences. The phototransistor is finally modified with Au contact on n-SnS2 , to be a more practical device displaying voltage output. Three different photo-logic states under blue, near infrared (NIR), and blue-NIR mixed photons are demonstrated using the voltage signals
Description:Date Revised 28.11.2023
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.202304599