Highly Sensitive Solar‐Blind Ultraviolet Photodetectors and 64 × 64 Photodetector Arrays Realized by Molecule Beam Epitaxy Grown Ga 2 O 3 Epitaxial Thin Films

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Gallium oxide (Ga 2 O 3 ) emerges as the most promising semiconductor for next‐generation solar‐blind UV photodetectors (SBPDs) because of its ultra‐wide bandgap of 4.85 eV. However, so far Ga 2 O 3 based SBPDs still suffer from problems such as high dark current and slow response speed. Herein, the fabrication of metal‐semiconductor‐metal (MSM) structures Ga 2 O 3 SBPDs with high performance using high‐quality Ga 2 O 3 epitaxial thin films grown by molecule beam epitaxy (MBE) is reported. The SBPDs are highly sensitive to solar‐blind UV spectrum and achieve a very low dark current of 273 fA at 10 V bias, a high specific detectivity of 1.6 × 10 16 Jones with a responsivity of 167 A W −1 , and a remarkedly rapid response speed with a decay time of 15 ms. The specific detectivity, dark current, and response speed of the SBPD achieve in this work are among the highest levels in the literature. The enhanced device performance is attributed to high crystalline quality of the film with reduced density of defects and fast photocarrier dynamics. Furthermore, a 64 × 64 photodetector array with high uniformity is fabricated on a 2‐inch Ga 2 O 3 epitaxial wafer, achieving the highest pixel count for Ga 2 O 3 photodetector array to date. This study paves the way for the development of fast‐speed Ga 2 O 3 SBPDs with high sensitivity and large‐scale photodetector arrays.