Seamless MoTe2 Homojunction PIN Diode toward 1300 nm Short‐Wave Infrared Detection. Issue 19 (27th June 2019)

• Record Type: Journal Article
• Authors: Lee, Han Sol; Lim, June Yeong; Yu, Sanghyuck; Jeong, Yeonsu; Park, Sam; Oh, Kyunghwan; Hong, Seongjin; Yang, Seunghoon; Lee, Chul‐Ho; Im, Seongil
• Is Part Of: Advanced optical materials. Volume 7:Issue 19(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-06-27
• Subjects: 2H‐MoTe2 -- Franz–Keldysh effect -- homojunctions -- PIN diodes -- SWIR detectors; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201900768
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Homojunction PN and PIN diodes based on 2D transition metal dichalcogenide (TMD) MoTe2 are reported in this work. Up to date, for PN junction diodes, type II‐based heterojunction diodes are mainly seen in report, but homojunction PN diodes using 2D‐layered materials are still rare although they enable seamless integration. Recently, hydrogen (H)‐doped n‐type MoTe2, achieved via atomic layer deposition (ALD) on top of a p‐type MoTe2 surface, was reported. Consequently, a lateral homojunction PN diode was realized by H‐doping. In fact, MoTe2 ‐based devices with a thickness on the order of nanometers can be applied for short‐wave infrared (SWIR) detection in the range of ≈1300 nm, a wavelength that Si‐based devices cannot properly address. Here, a seamless MoTe2 homojunction PIN diode is demonstrated, achieving the detection of visible to 1300 nm SWIR photons. This thin MoTe2 initially forms a PN junction by selective H‐doping, but a PIN diode is even obtained using two split gates. Compared to the PN diode mode, the PIN mode greatly enhances the photoresponse in the visible to 1300 nm wavelength range because of the increased built‐in electric field. The Franz–Keldysh effect is regarded strongly responsible for the effective absorption of 1300 nm SWIR photons in MoTe2 . It is anticipated that this development may support Si photodetectors for integration on Si devices. Abstract : Homojunction MoTe2 PIN diode is first demonstrated, enabling the detection of visible‐to‐1300 nm short‐wave IR photons. This 2D‐like MoTe2 device changes its mode from PN to PIN using two split gates. Compared to PN, the PIN mode much enhances the photoresponse in visible‐to‐1300 nm IR range. Franz–Keldysh effect is regarded responsible for 1300 nm IR absorption in MoTe2 .