Stabilization of MAPbI3Nanocrystals by Dual Ligands for Photodetectors

Abstract

Organohalide perovskite nanocrystals (OHPNCs) and their wide range of optoelectronic applications have attracted much interest due to their unparalleled photoluminescent intensity and quantum efficiency. Furthermore, their bandgap is tunable over the visible and near-infrared wavelengths through changes in composition, shape, or size. The main challenge of applying OHPNCs is that they are unstable under ambient conditions due to their high reactivities with moisture and facile cubic-to-tetragonal phase transitions at room temperature. In this study, we have achieved ambient-stable, cubic-phase OHPNCs through a dual-ligand approach with both oleic acid (OA) and oleylamine (OLA). Furthermore, it was shown that these ambient-stable OHPNCs could be made into photodetectors exhibiting a responsivity of 0.02 A/W, when illuminated with a 470 nm wavelength light and in a bias electric field of 4 × 105 V/m, which was higher than those of current commercially available silicon-based photodetectors.