Ti3C2/ϵ-Ga2O3 Schottky Self-Powered Solar-Blind Photodetector With Robust Responsivity

As a 2D material, MXene has emerged as an excellent electrode material for optoelectronic devices due to its high conductivity and hydrophilic surface. Here, the Ti
₃
C
₂
-based MXene was employed to construct the Ti
₃
C
₂
/ϵ-Ga
₂
O
₃
Schottky junction photodetector. The fabricated device demonstrated a self-powered operation manner with an extremely low dark current (0.07 pA), an outstanding light on/off switch ratio (2.5×10
⁶
), a remarkable photo-response speed (43 ms/145 ms), a responsivity (R) of 15.5 mA/W, an external quantum efficiency (EQE) of 7.5% and a detectivity (D*) of 2.15×10
¹¹
Jones. Such excellent photodetection performance that is comparable or even higher than those of Ga
₂
O
₃
Schottky photodetectors previously reported are originated from the excellent conductivity of MXene, good crystallization of ϵ-Ga
₂
O
₃
, and their well-matched energy level. Additionally, our Schottky junction device is capable of sensing solar-blind UV region and exhibits excellent stability in the air environment. The perfect combination of 2D MXene and wide-bandgap ϵ-Ga
₂
O
₃
proposes a novel route for the self-powered Schottky devices.