Geometric parameter optimization to minimize the light‐reflection losses of regular vertical silicon nanorod arrays used for solar cells

We theoretically investigate the light-reflection properties of silicon nanorod (SiNR) arrays with square and hexagonal alignments. The reflectivity of photon flux (RPF) is introduced to evaluate the light-reflection capability of SiNR arrays. The quantum efficiency (QE) varies on changing the geometric parameters of SiNR arrays. The optimal geometric parameters of SiNR arrays corresponding to maximum QE of 92.4% are achieved. The optimum ratio (SiNR diameter divided by the array periodicity) is 0.72 for the square arrays and 0.67 for the hexagonal arrays, and the optimum SiNR length for both alignments is the same with a value of 0.090 μm. In addition, the optimal geometric parameters are independent of the array density.