n‐Type GaSe Thin Flake for Field Effect Transistor, Photodetector, and Optoelectronic Memory

• Published in: Advanced electronic materials Vol. 10; no. 8
• Main Authors: Kumar, Arun, Pelella, Aniello, Intonti, Kimberly, Viscardi, Loredana, Durante, Ofelia, Giubileo, Filippo, Romano, Paola, Neill, Hazel, Patil, Vilas, Ansari, Lida, Hurley, Paul K., Gity, Farzan, Di Bartolomeo, Antonio
• Format: Journal Article
• Language: English
• Published: Wiley-VCH 01.08.2024
• Subjects: 2D materials; density functional theory; field effect transistor; GaSe; optoelectronic memory; photodetector
• DOI: 10.1002/aelm.202400010
• ISSN: 2199-160X

The family of 2D chalcogenide semiconductors has been growing rapidly. Metal monochalcogenides, for instance, can enable new possibilities in functional electronics and optoelectronics. A Gallium Selenide (GaSe) thin flake is used to fabricate a back gated field effect transistor (FET) with n‐type conduction behavior and wide hysteresis at the ambient conditions. The device shows high mobility up to 28 cm2 V−1 s−1 with Ion/Ioff ratio over 103. Under the laser exposure, the device shows a decrease in the threshold voltage and a left‐shift of the transfer characteristic with a slight increase in the current. The transfer characteristic exhibits a hysteretic behavior with hysteresis width linearly dependent on the applied gate voltage. Moreover, the GaSe‐based FET shows a photo response with a photoresponsivity of 475 mAW−1 and detectivity of 4.6 × 1012 Jones. The photocurrent rise and decay times are 0.1 and 1.3 s, respectively. Furthermore, the GaSe FET device can be used as a performant memory device with well separated states and memory window enhanced by the laser exposure, confirming an optoelectronic memory class. Gallium–Selenide (GaSe) thin‐flake shows n‐type conduction in a field‐effect transistor with Ni contacts. The transfer characteristic exhibits a hysteretic behavior and high photo response, which are exploited to demonstrate an optoelectronic memory device.