Nanowire Perovskite Solar Cell

Organolead iodide perovskite, CH₃NH₃PbI₃, was prepared in the form of nanowire by means of a small quantity of aprotic solvent in two-step spin-coating procedure. One-dimensional nanowire perovskite with the mean diameter of 100 nm showed faster carrier separation in the presence of hole transporting layer and higher lateral conductivity than the three-dimensional nanocuboid crystal. Reduction in dimensionality resulted in the hypsochromic shift of both absorption and fluorescence spectra, indicative of more localized exciton states in nanowires. The best performing device employing nanowire CH₃NH₃PbI₃ delivered photocurrent density of 19.12 mA/cm², voltage of 1.052 V, and fill factor of 0.721, leading to a power conversion efficiency (PCE) of 14.71% at standard AM 1.5G solar illumination. A small I–V hysteresis was observed, where a PCE at forward scan was measured to be 85% of the PCE at reverse scan.