Quantum-Confined 0D/2D/3D Heterostructure Photodetectors with an Ultrafast Self-Powered Broadband Response for Short-Wave Infrared Imaging

The integration of quantum-confined nanostructures with two-dimensional (2D) and three-dimensional (3D) materials presents a promising avenue for advancing optoelectronic devices, yet achieving synergistic enhancement in broadband detection, self-powered operation, and ultrafast response remains challenging. Here, a novel 0D/2D/3D heterostructure photodetector is demonstrated by integrating PdTe₂ quantum islands (QIs) with PtTe₂ and n^--Ge, leveraging quantum confinement, van der Waals interfacial coupling, and light-trapping mechanisms. The unique architecture enables broadband photodetection spanning 532-2200 nm, overcoming the intrinsic absorption limit of Ge above 1850 nm. The strong built-in electric field at the PtTe₂/Ge interface facilitates self-powered operation, yielding an ultralow dark current (∼10^-7 A) and a high rectification ratio (10⁴). Remarkably, the device achieves a record-high responsivity of 353 mA/W and detectivity of 2.43 × 10¹¹ Jones at 1550 nm, along with the rise/fall times (τ_r/τ_f) being as short as 14 μs/20 μs, outperforming most reported 2D/3D heterostructure-based detectors. The scalable fabrication of an 8 × 8 pixel array with uniform photoresponse further highlights its potential for high-resolution short-wave infrared imaging. This work establishes a paradigm for combining 0D quantum structures with 2D/3D materials to transcend conventional performance limits, offering a cost-effective, CMOS-compatible platform for next-generation sensing, communication, and on-chip photonic systems.