Interband Carrier Relaxation‐Enabled Synaptic‐Like Luminescence in Multi‐Heteroatom‐Doped Diamond for Photonic Synapses and Image Denoising

ABSTRACT

Precise luminescence control of materials is a prerequisite for the development of emerging nanophotonic applications. However, existing strategies rely on static material designs. Herein, we develop a multiple heteroatom doping strategy to synthesize diamonds with synaptic‐like luminescence and demonstrate their precise luminescence modulation for all‐optical neuromorphic applications. Through high‐pressure and high‐temperature synthesis with multiple heteroatom catalysts, the resulting bulk monocrystal diamonds exhibit novel fluorescence and phosphorescence that depend on laser frequency and pump duration, similar to the behavior of synaptic response to different neural signals. Experimental and theoretical analyses reveal that the multiple heteroatom catalysts introduce four kinds of boron‐related donor‐acceptor pairs, which serve as recombination centers for multiple‐emissive fluorescence and phosphorescence. Meanwhile, the interband carrier relaxation among different heteroatom donors gives rise to a novel excited electron dynamic process, resulting in the optical responses that depend on excitation wavelength, laser frequency, and pump duration. By leveraging this synaptic‐like responsive luminescence, the diamond demonstrates robust synaptic plasticity through precisely controlled excitation dynamics, showing promising potential in neuromorphic computing and image denoising. These findings establish a new foundation for precise luminescence engineering in solid‐state materials and offer valuable insights for the design of tailored all‐optical neuromorphic devices.