Enhanced band-filling effect in halide perovskites via hydrophobic conductive linkers

Defect-Passivated Photosensor Based on Cesium Lead Bromide (CsPbBr3) Perovskite Quantum Dots for Microbial Detection

“…Passivation of halide vacancy in perovskite increased charge carrier lifetime and reduced the trap-state density, as shown in Figures and . These changes reduce the possibility of trapping electrons and increase the density of electrons, which contributes to filling band-edge states, resulting in an increment of the bandgap. , Second, it passivates the trap states near the conduction and valence bands, increasing the bandgap. − The defect passivation shifted the PL peak to a shorter wavelength. Third, the vacancy passivation with halides of parylenes was observed to increase the bandgap.…”

“…These changes reduce the possibility of trapping electrons and increase the density of electrons, which contributes to filling band-edge states, resulting in an increment of the bandgap. 43,44 Second, it passivates the trap states near the conduction and valence bands, increasing the bandgap. 45−47 The defect passivation shifted the PL peak to a shorter wavelength.…”

Thermally Evaporated MAPbBr3 Perovskite Random Laser with Improved Speckle-Free Laser Imaging

“…25−28 However, smaller grain sizes will also bring more grain boundaries, resulting in more uncoordinated ion defects, especially the uncoordinated Pb 2+ ion, which acts as the nonradiative recombination center in the perovskite layer, decreasing the device efficiency and stability. 29 Defect passivation is an efficient strategy for reducing the uncoordinated ion defects in MHP films by introducing passivating agents and has been adopted to improve the quality of MHP films. 30−33 Lewis base additives e.g., TPPO have been proved to be effective passivating agents in solvent engineering.…”

“…Great research efforts toward improving the performance of thermally evaporated perovskite materials and devices have been made. − Early attempts to increase the radiative recombination rate are aimed at reducing grain sizes, including evaporation rate adjustment and annealing temperature regulation. − However, smaller grain sizes will also bring more grain boundaries, resulting in more uncoordinated ion defects, especially the uncoordinated Pb 2+ ion, which acts as the nonradiative recombination center in the perovskite layer, decreasing the device efficiency and stability . Defect passivation is an efficient strategy for reducing the uncoordinated ion defects in MHP films by introducing passivating agents and has been adopted to improve the quality of MHP films. − Lewis base additives e.g., TPPO have been proved to be effective passivating agents in solvent engineering. − Through attaching an organophosphorus ligand (PO group) to the surface and grain boundaries of MHP films forming the PO–Pb bond with the uncoordinated Pb 2+ ion, nonradiative recombination would be reduced and the corresponding light emission efficiency would be significantly increased. ,, Therefore, it is expected that adopting the TPPO approach to thermally evaporated perovskite films will reduce defect density and hence prompt the development of high-performance ASE and lasing.…”