High Performance β-Ga2O3 Solar-Blind Metal–Oxide–Semiconductor Field-Effect Phototransistor With Hafnium Oxide Gate Dielectric Process

This letter demonstrates a high performance β-Ga
₂
O
₃
solar-blind metal-oxide-semiconductor field-effect phototransistor (SBPT) with Hafnium Oxide (HfO
₂
) Gate Dielectric. The SBPT shows a high Photo-to-dark-current ratio (PDCR) of 6.9×10
⁷
, an I
_{254 nm}
/ I
_{365 nm}
rejection ratio of 6.0×10
⁷
combined with an external quantum efficiency (EQE) of 6.4×10
⁷
%. In addition, benefit from stronger control capability of the HfO
₂
based gate structure, the fabricated SBPT reaches a record detectivity ( D *) of 1.1×10
¹⁹
Jones and ultrahigh responsivity ( R) of 1.4×10
⁷
A/W. Furthermore, short decay time ( τ
_d
) is obtained to be as low as 16 ms. These outstanding properties indicate that SBPT is promising for the solar-blind detection.