An in-plane WSe2 p–n homojunction two-dimensional diode by laser-induced doping. Issue 25 (15th June 2020)

• Record Type: Journal Article
• Authors: Yang, Sujeong; Lee, Geonyeop; Kim, Janghyuk; Yang, Seunghoon; Lee, Chul-Ho; Kim, Jihyun
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 25(2020)
• Page Start: 8393
• Page End: 8398
• Publication Date: 2020-06-15
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tc01790f
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Laser-treatment was used to take p-doping effects on WSe2 locally, which induce in-plane WSe2 p–n homojunction. Abstract : Conventional doping schemes of Si microelectronics are inadequate for atomic-thickness two-dimensional (2D) semiconductors, which makes it challenging to construct 2D p–n homojunctions. Herein, a UV laser-assisted doping method with addressability is proposed for seamlessly building a 2D WSe2 p–n homojunction. WSe2 with ambipolar transport properties was exposed to a focused UV laser to form WO x in a self-limiting and area-selective process that induces hole doping in the underlying WSe2 via electron transfer. Different electrical behaviors, ranging from p–p to p–n in-plane homojunctions, were observed between the as-exfoliated (ambipolar) region and the UV laser-treated (p-doped) region, under the electrostatic modulation of the back-gate bias ( V BG ), resulting in the multi-state rectification ratios of 895 (positive V BG ) and ∼4 (negative V BG ). The evolution of the depletion region in the WSe2 in-plane homojunction was analyzed at different V BG using the scanning photocurrent mapping approach, yielding a high photocurrent of 1.8 nA for positive V BG, owing to the development of the p–n junction. Finally, a WSe2 -based 2D homogeneous complementary inverter is demonstrated with a voltage gain of 1.8, thereby paving the way for next-generation atomic-thickness circuitry.