Asymptotic analysis of subwavelength halide perovskite resonators

Halide perovskites are promising materials with many significant applications in photovoltaics and optoelectronics. Their highly dispersive permittivity relation leads to a non-linear relationship between the frequency and the wavenumber. This, in turn, means the resonance of the system is described by a highly non-linear eigenvalue problem, which is mathematically challenging to understand. In this paper, we use integral methods to quantify the resonant properties of halide perovskite nano-particles. We prove that, for arbitrarily small particles, the subwavelength resonant frequencies can be expressed in terms of the eigenvalues of the Newtonian potential associated with its shape. We also characterize the hybridized subwavelength resonant frequencies of a dimer of two halide perovskite particles. Finally, we examine the specific case of spherical resonators and demonstrate that our new results are consistent with previous works.