The luminescent nature of plasmonic nanoparticles (NPs) has been intensively investigated in recent years. Plasmon-enhanced electronic Raman scattering and the radiation channels of metallic photoluminescence (PL) involving conventional carrier recombinations and emergent particle plasmons are proposed in the past few decades but largely limited to weak excitation regimes. Here, we systematically examine the PL evolution of plasmonic NPs under different excitation power levels. The spectral resonances and chromaticity of PL are investigated within and beyond the scope of geometry conservation. Results indicate the nature of PL in plasmonic NPs could be a process of graybody radiation, including one factor of plasmonic emissivity in the weak excitation regime and the other factor of blackbody radiation in the strong excitation regime. This comprehensive analysis provides a fundamental understanding of the luminescent nature of plasmonic NPs and highlights their potential applications in transient temperature detection at the nanometer scale.

中文翻译：

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等离激元纳米粒子在弱和强激发态下的金属光致发光

近年来，等离子体纳米颗粒（NP）的发光性质得到了深入研究。等离激元增强电子拉曼散射和涉及传统载流子复合和涌现粒子等离激元的金属光致发光（PL）辐射通道在过去几十年被提出，但很大程度上仅限于弱激发机制。在这里，我们系统地研究了等离激元纳米粒子在不同激发功率水平下的PL演化。在几何守恒范围内和之外研究 PL 的光谱共振和色度。结果表明，等离子体纳米粒子中的PL的本质可能是灰体辐射过程，其中一个因素是弱激发态下的等离子体发射率，另一个因素是强激发态下的黑体辐射。这种全面的分析提供了对等离子体纳米粒子的发光性质的基本了解，并强调了它们在纳米尺度瞬态温度检测中的潜在应用。