Improved UV Photodetection Based on β-Ga2O3-NiO 1D–1D Heterostructure Arrays

Ultraviolet (UV) photodetectors (PDs) based on β-Ga
₂
O
₃
/NiO (1D–1D) heterostructure (HS) and β-Ga
₂
O
₃
/p-Si (1D–3D) HS are fabricated on a p-type Si substrate using the glancing angle deposition technique. The images acquired from a field emission scanning electron microscope show the formation of well-aligned vertical 1D–1D HS between β-Ga
₂
O
₃
and NiO materials and 1D–3D HS between β-Ga
₂
O
₃
and p-Si substrates. Moreover, the high-resolution transmission electron microscope images confirm the formation of 1D–1D HS with β-Ga
₂
O
₃
nanowire (NW) at the top and NiO NW at the bottom. On comparing, the 1D–1D HS UV PD shows a very high responsivity of 185.25 A/W, a detectivity of 3.86 × 10
¹³
Jones, a noise equivalent power of 8.70 × 10
⁻¹⁴
W, and an external quantum efficiency of 835.35% at a wavelength of 275 nm. Moreover, the 1D–1D HS UV PD shows faster response (with rise time and fall time of 0.11 and 0.25 s, respectively) than that of the 1D–3D HS UV PD and is also found to be better than some of the recently reported UV PDs.