Jorudas Justinas, Rehman Hamza, Cojocari Maria, Pashnev Daniil, Urbanowicz Andrzej, Kašalynas Irmantas, Bertoni Benedetta, Vicarelli Leonardo, Pitanti Alessandro, Malykhin Sergei, Svirko Yuri, Kuzhir Polina, Fedorov Georgy
Department of Physics and Mathematics, Center of Photonics Research, University of Eastern Finland, Yliopistokatu 7, FI-80101 Joensuu, Finland.
Department of Optoelectronics, Center for Physical Sciences and Technology (FTMC), Saulėtekio av. 3, LT-10257 Vilnius, Lithuania.
Nanotechnology. 2024 May 9;35(30). doi: 10.1088/1361-6528/ad4157.
Fifty percents absorption by thin film, with thickness is much smaller than the skin depth and optical thickness much smaller than the wavelength, is a well-known concept of classical electrodynamics. This is a valuable feature that has been numerously widely explored for metal films, while chemically inert nanomembranes are a real fabrication challenge. Here we report the 20 nm thin pyrolyzed carbon film (PyC) placed on 300 nm thick silicon nitride (SiN) membrane demonstrating an efficient broadband absorption in the terahertz and near infrared ranges. While the bare SiNmembrane is completely transparent in the THz range, the 20 nm thick PyC layer increases the absorption of the PyC coated SiNmembrane to 40%. The reflection and transmission spectra in the near infrared region reveal that the PyC film absorption persists to a level of at least 10% of the incident power. Such a broadband absorption of the PyC film opens new pathways toward broadband bolometric radiation detectors.
薄膜吸收50%，其厚度远小于趋肤深度且光学厚度远小于波长，这是经典电动力学中一个众所周知的概念。这是一个有价值的特性，已在金属薄膜中得到广泛研究，而化学惰性纳米膜的制造是一项真正的挑战。在此，我们报告了置于300nm厚氮化硅（SiN）膜上的20nm厚热解碳膜（PyC），其在太赫兹和近红外波段表现出高效的宽带吸收。虽然裸SiN膜在太赫兹波段完全透明，但20nm厚的PyC层使涂覆有PyC的SiN膜的吸收增加到40%。近红外区域的反射和透射光谱表明，PyC膜的吸收持续到至少入射功率的10%。PyC膜的这种宽带吸收为宽带测辐射热辐射探测器开辟了新途径。
