Huo Dewang, Zhang Jingwen, Wang Yingce, Wang Chao, Su Hang, Zhao Hua
Institute of Modern Optics, Department of Physics, Harbin Institute of Technology, Harbin 150001, China.
Key Laboratory of Micro-Optics and Photonics Technology of Heilongjiang Province, Harbin 150001, China.
Nanomaterials (Basel). 2018 Jul 1;8(7):485. doi: 10.3390/nano8070485.
Based on an integrated array of refractory titanium nitride (TiN), a metasurface perfect absorber (MPA) in the visible-to-near infrared (NIR) band is reported. The systematic and detailed simulation study of the absorption of the MPA is performed with the finite-different time-domain (FDTD) method. Tailoring the structure, the MPA realizes as high an average as 99.6% broadband absorption, ranging from 400 nm to 1500 nm. The broadband perfect absorption can be attributed to localized surface plasmonic resonance (LSPR), excited by the continuous diameter evolution from the apex to the base of the nanocone, and the gap plasmons excited among the nanocones, as well as in the spacer layer at longer wavelengths. Particularly, the coupling of the resonances is essentially behind the broadening of the absorption spectrum. We also evaluated the electric field intensity and polarization-dependence of the nanocone MPA to offer further physical insight into light trapping capability. The MPA shows about 90% average absorption even at an oblique incidence up to 50°, which improves the acceptance capability of light-harvesting system applications. This unique design with the TiN nanocone array/aluminium oxide (Al₂O₃)/TiN structure shows potential in imminent applications in light trapping and thermophotovoltaics.
基于由难熔氮化钛（TiN）构成的集成阵列，报道了一种在可见光至近红外（NIR）波段的超表面完美吸收体（MPA）。采用时域有限差分（FDTD）方法对该MPA的吸收进行了系统且详细的模拟研究。通过调整结构，该MPA在400纳米至1500纳米范围内实现了高达99.6%的宽带平均吸收。宽带完美吸收可归因于局域表面等离子体共振（LSPR），其由纳米锥从顶部到底部直径的连续变化激发，以及纳米锥之间以及较长波长下间隔层中激发的间隙等离子体。特别地，共振的耦合本质上是吸收光谱展宽的原因。我们还评估了纳米锥MPA的电场强度和偏振依赖性，以进一步深入了解其光捕获能力。即使在高达50°的斜入射情况下，该MPA仍显示出约90%的平均吸收，这提高了光捕获系统应用的光接受能力。这种具有TiN纳米锥阵列/氧化铝（Al₂O₃）/TiN结构的独特设计在光捕获和热光伏的紧迫应用中显示出潜力。
