Excellent surface plasmon and hot carrier properties of transition metal nitride at different temperatures

Abstract

Plasmonic materials that exhibit excellent plasmonic behavior at high temperatures would greatly expand existing applications, but the search for such materials is ongoing. Transition metal nitrides with good conductivity and high-temperature stability are promising candidates for temperature-dependent plasmonic applications. Here, we systematically investigate the temperature-dependent surface plasmon and hot carrier properties of TiN and VN. Significantly, high temperatures significantly affect the phonon-assisted intraband transition processes. Meanwhile, TiN and VN exhibit efficient optical absorption and low surface plasmon loss at different temperatures, which are comparable to or even higher than Ag. In particular, the surface plasmon response of TiN extends to visible light, making it an excellent candidate for low-loss and broadband plasmonic applications at high temperatures. In contrast, VN exhibits a much narrower plasmonic window, which is mainly suitable for infrared low-loss plasmonic devices. For hot carriers, the energy and probability distributions of hot holes in TiN and hot electrons in VN exhibit robustness to temperature. Meanwhile, transport properties indicate that the temperature effect on hot holes is significantly higher than that on hot electrons in TiN and VN. Therefore, we expect that the reported results will provide theoretical guidance for the design of next-generation high-temperature plasmonic devices.