MAPbI3 perovskite hybrid metasurface for agile, multidimensional THz wave modulation with 3D Dirac semimetal-like Fermi model optically induced by three wavelength bands

Abstract

Organic–inorganic hybrid three-dimensional (3D) perovskite materials have emerged as potential candidates for terahertz (THz) modulators. In this study, the metasurface of electromagnetically induced transparency resonance was integrated with 3D perovskite to achieve a high-efficiency dynamic THz modulator. The integration was achieved by modulating the intrinsic optoelectronic properties of perovskite with three wavelengths of optical pump and external voltage excitation. The maximum modulation depth was 466.8 %, with a pump flux of 11.5 mW/cm2 and excitation at 532 nm. The Dirac-like semimetal-Fermi energy band model was proposed to explain the dynamic transitions of free carriers in perovskites and reveal the internal mechanism of the dynamic modulation. In addition, we verified our proposed theoretical model by simulation and theoretical fitting, and calculated the conductivity and number of free carriers of perovskite under different excitations. The system thoroughly explains the observed differences under three wavelengths of optical pump excitation. The active control of THz waves based on Dirac semimetal materials with optical and electrical inputs could have many potential applications that have been proposed by few studies.

Keywords

• THz modulator
• 3D perovskites
• EIT metasurface
• Dirac–Fermi model