Achieving Ultra-Low Dark Current in β-Ga₂O₃ Photoconductive Photodetectors for Anti-Interference Optical Human–Machine Interaction Systems via Gallium Interstitials Engineering

Driven by the demand for high-throughput data transmission, the development of cost-effective and highly sensitive photoconductive photodetectors has become imperative to advance optical communication systems, thereby playing a crucial role in the realm of human–machine interaction. This study presents a β-Ga₂O₃ photoconductive photodetector employed in an anti-interference optical human–machine interaction system that demonstrates superior responsivity and minimized dark current, attributed to the strategic modulation of intrinsic defects. Through first-principles simulations, the defect dynamics across various growth conditions are systematically elucidated, enabling the precise synthesis of β-Ga₂O₃ films with markedly diminished shallow-donor gallium interstitials. A super low dark current of 4.15 × 10⁻¹² A is achieved even under 40 V bias, accompanied by high responsivity of 2.26 A·W⁻¹ and superior detectivity realizing of 1.14 × 10¹⁴ Jones. Ultimately, β-Ga₂O₃ photodetector is employed in human–machine interaction systems for robot arm control, which enables the system to demonstrate excellent resistance to random noise, which facilitates the integration of more efficient algorithms. Consequently, the system achieves an 88.46% reduction in reading time and a 78.17% reduction in required storage space, thereby demonstrating the substantial potential of cost-effective, highly sensitive β-Ga₂O₃ in the era of the Internet of Things.