Ultra-Sensitive Optoelectronics Enabled by Atomically Tailored Interfaces Engineering for Advanced Perceptual Imaging

Abstract

Ultra-weak light detection represents a critical enabling technology for next-generation imaging, remote monitoring, and autonomous systems, where efficient charge transfer is essential to achieve ultralow detection thresholds. Herein, an interfacial lattice-distortion engineering strategy is proposed by selectively substituting phenylethyl ammonium (PEA) cations with 4-chlorophenylethylammonium (Cl-PEA) at perovskite heterointerfaces. This substitution induces beneficial octahedral distortions, boosting hole transport efficiency in few-layer 2D perovskites by 26%. When integrated with MoS₂/WSe₂ heterostructures, the optimized van der Waals contact and enhanced energy-level alignment yield a high-performance photodetection, including a responsivity of 2.7 × 10⁴ A/W, a detectivity up to 5.26 × 10¹⁴ Jones, and an exceptionally low noise equivalent power of 0.42 fW Hz^−1/2. Notably, the device operates self-powered at incident power densities as low as 0.54 µW cm⁻², enabling real-time, on-chip image processing even under dim-light conditions. This functionality is further utilized for noise reduction in traffic-light images prior to object detection with YOLOv11 network, establishing a direct bridge between device-level photodetection and machine-learning-driven recognition. This interfacial lattice distortion engineering paradigm in van der Waals-contacted 2D devices opens new avenues for designing ultrasensitive, low-noise, and functionally integrated optoelectronic devices.