Optimization of the Nanowire Size and Distribution of Compound Semiconductor Nanowire-Based Hybrid Solar Cells

The hybrid solar cell (HSC) with an inorganic semiconductor and polymer materials forming an active layer comprises an important class of organic photovoltaics. In this study, the performance of the inorganic nanowire (NW)-based HSC was simulated with different NW size and density within the active layer. The model of mixture active layer has been established, and a design example was provided based on GaAs NWs as the acceptor and poly(3-hexylthiophene-2,5-diyl) (P3HT) polymer as the donor. Using the proposed model, it is obtained that the optimal external quantum efficiency, current density-voltage (J-V) characteristic, and power conversion efficiency (PCE) can be obtained by varying the NWs´ center-to-center distance, as well as their radius. It is concluded that when the separation of NWs is fixed at 50 nm, the optimized radius of the NW is 20 nm. While the NW radius is kept as 10 nm, the optimized center-to-center distance between the NWs is 28 nm. The highest short-circuit currents of the HSC are 12.69 and 13.35 mA/cm² for the two optimized conditions, whereas the PCEs of the devices are 14.41% and 15.05%, respectively. The simulation results compare well with the current literature using the same material and, thus, provide an effective method for the HSC design.