Refractory plasmonic metasurface absorber controlled by tuning of stoichiometry
Ragini Mishra1*, Ching-Wen Chang2, Abhishek Dubey3, Zong-Yi Chiao4, Ta-Jen Yen3, Yu-Jung Lu2,4, Shangjr Gwo1,5,2
1Institute of Nanoengineering Microsystem, National Tsing Hua University, Hsinchu, Taiwan
2Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan
33Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
4Department of Physics, National Taiwan University, Taipei, Taiwan
5Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
* Presenter:Ragini Mishra,

Titanium nitride (TiN) extensively used in plasmonic applications owing of its refractory property, compatible for complementary metal oxide semiconductor (CMOS) used as broadband absorber, insensitive to light polarization and scalable method fabrication which is essential in solar thermophotovoltaics (STPV). High-efficiency solar energy harvesting has become increasingly essential to meet the green energy requirement. As present, solar thermophotovoltaic device is considered to exceed the Shockley–Queisser limit for energy conversion efficiency. In this work, we demonstrated first time single layer epitaxial TiN metasurface (nonohole array) broadband absorber with average absorptivities of 90% over wide range in visible regime. Geometrical parameters of TiN metasurface effect for the broadband absorption has been designed and analysed by using finite difference time domain (FDTD) numerical methods. Broadband absorption in the visible regime is accomplished by combining the plasmonic characteristics of metasurface and intrinsic loss of TiN film. As we know epitaxial MBE TiN has better thermal property compare with sputter TiN.

Keywords: Titanium Nitride, Solar thermophotovoltaics, Metasurfaces, Plasmonics