Theoretical research of resonance properties of metal-dielectric gratings is presented. These gratings are two-dimensional periodic structures formed by the dielectric nanorods, which stand on the multilayer structure, which consists of metal and dielectric nano films.

Theoretical results obtained are based on the rigorous solution of the integral differential volume equation by dint of the Galerkin’s method for the diffraction of electromagnetic waves which incident on the 2-d periodic diffraction grating. The final value of the dielectric permeability of metals is considered.

New diffraction grating obtained can absorb more than 90% of the solar energy of the radiation in a wide range of wavelengths and angles of incidence.

It is shown that the use the wavelength of the resonance absorption depends on the type of material of the metal film and the use of two films of different metals results in a broadband absorption.

The result obtained can be applied in the solar battery design.