Optical absorption enhancement of the GaInAsSb nanopillar arrays for infrared detector

GaInAsSb has an important application value in the field of infrared photoelectricity. In this paper, the optical properties of Ga[Formula: see text]In[Formula: see text]As[Formula: see text]Sb[Formula: see text] nanopillar arrays with different shapes are studied by using the finite-difference time-domain (FDTD) method. The simulation results show that the peaks of all structures occur at 950[Formula: see text]nm to 1100 nm bands and peak up to 97%. Among them, the period and height of the nanopillars and the inclination angle of the incident light will significantly affect the size of the absorption peak of the nanopillars, but not the peak position. However, with the increase of the diameter, the absorption peak of the nanoparticles showed a trend of increasing first and then decreasing, and the peak position of the absorption peak showed a significant redshift. In addition, for the triangular prism structure, its absorption rate in the array structure with high duty cycle is higher than 90%, which provides an important reference for the preparation of high-density integrated infrared optical detector.