The device applications of β-Ga2O3 semiconductors are limited by the absence of effective acceptors to form β-Ga2O3 p-n homojunctions. Herein, a WSe2/β-Ga2O3 p-n heterojunction formed by van der Waals interaction was exposed to an area-selective He-Cd UV laser (wavelength: 325 nm), increasing the hole carrier concentrations in the ambipolar WSe2 layer via the self-limited formation of WOX with a high electron affinity. The device parameters (on-resistance, on/off current ratio, and ideality factor) of the WSe2/β-Ga2O3 heterojunction p-n diode were systematically evaluated under UV laser treatment of different durations; an ideality factor of as low as 1.2 was obtained after 600 s. A β-Ga2O3 junction field-effect transistor (JFET) with a p-WSe2 heterojunction top-gate exhibited excellent transport characteristics, including a lower subthreshold swing, higher on/off output ratio, and improved field-effect carrier mobility than pristine β-Ga2O3 heterojunction FETs. Heterostructure formation by the introduction of two-dimensional p-WSe2 is an innovative method to demonstrate Ga2O3-based p-n diodes and JFETs, which can advance the applications of ultra-wide bandgap β-Ga2O3 electronic and optoelectronic devices.
Bibliographical noteFunding Information:
This research was financially supported by the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration and Ministry of Trade (18-CM-50-65), and the National Research Foundation of Korea (2020M3H4A3081799).
© 2022 The Royal Society of Chemistry
ASJC Scopus subject areas
- General Chemistry
- Materials Chemistry