Abstract
        In this paper, we investigate the different forms of photonic crystal geometries and calculate the absorption diagrams and 
we try to obtain the maximum absorption. The effects of size and the number of photonic crystal holes and their shapes 
have been studied. The proposed structures can have absorption coefficients of higher than 98%. The dielectric function of 
the gallium arsenide layer is calculated by Maxwell Garnet model.
        Keywords
        Two dimensions’ photonic crystals, Size effect, Different shapes of photonic crystal holes, Maxwell-Garnet Model, Absorption spectrum.
        Citation
        M. SOLAIMANI, PARISA MAHMOUDI, Investigation of the effect of photonic crystal geometry on  the absorption spectrum, Optoelectronics and Advanced Materials - Rapid Communications, 15, 11-12, November-December 2021, pp.528-537 (2021).
        Submitted at: June 12, 2021
 
        Accepted at: Nov. 24, 2021