Decyl disulfide surface treatment improved photoluminescence quantum yield and stability of blue-emitting CsPbBr3 nanoplatelets

Ultrastable Photodetectors Based on Blue CsPbBr3 Perovskite Nanoplatelets via a Surface Engineering Strategy

“…Excitingly, ATDA treatment effectively addresses this issue, leading to longer PL lifetimes and slower TA decay processes. The PL decay curves and TA data collectively demonstrate that ATDA can effectively reduce the number of nonradiative defects on the surface of NPLs, significantly enhancing their PLQY and photo- and thermal stability. − …”

“…The blue shift is attributed to a decrease in the valence band potential and an increase in the conduction band potential, resulting from lattice expansion. 24,25 The PL peak of the pristine NPLs showed a significant red shift from 280 to 380 K compared with that of the ATDA-treated NPLs, which may be attributed to the aggregation of the pristine NPLs. The exciton binding energy of the ATDA-treated NPLs was determined to be 198 meV by fitting the PL intensity as a function of inverse temperature, significantly higher than that of the pristine NPLs with a value of 69 meV, which further evidences that ATDA treatment can passivate the surface vacancy defects of NPLs and reduce the undercoordination of Pb atoms and electron trapping, thereby enhancing their stability.…”

“…Figure a,d reveals that the ground-state bleaching of the ATDA-treated NPLs is significantly greater than that of the pristine NPLs . The population of the higher-energy states has a shorter duration, indicating that the hot excitons relax more readily to the band edge instead of being delayed by surface defects or other capture processes. − Additionally, the bleaching recovery kinetics of the ATDA-treated NPLs are noticeably slower (Figure b,e). When the ground-state bleaching was recovered to half, the ATDA-treated NPLs exhibited a significantly increased recovery time of 223.32 ps compared to 114.01 ps for pristine ones.…”

“…26,35 As shown in Figure S13, for the pristine CsPbBr 3 NPLs, water molecules and oxygen in the environment are easily adsorbed on the surface defect sites of NPLs, which can induce the phase transition or decomposition of NPLs by introducing vacancies into the crystal lattice. 9,24,26 In the case of ATDA-treated CsPbBr 3 NPLs, ATDA ligands were attached to the NPL surface by the dicarboxyl groups to build a compact and densely packed barrier layer around the NPLs, passivating surface defects and preventing the adsorption of water molecules and oxygen onto the surface of CsPbBr 3 NPLs. 26 The performance comparison of the CsPbBr 3 NPL/ nanosheet photodetectors is summarized in Table 1.…”

“…The excellent stability and performance of the ATDA-treated NPL photodetectors are mainly attributed to the following reason. ATDA can effectively passivate surface defects and improve the stability and charge transfer efficiency of the photodetector. , As shown in Figure S13, for the pristine CsPbBr 3 NPLs, water molecules and oxygen in the environment are easily adsorbed on the surface defect sites of NPLs, which can induce the phase transition or decomposition of NPLs by introducing vacancies into the crystal lattice. ,, In the case of ATDA-treated CsPbBr 3 NPLs, ATDA ligands were attached to the NPL surface by the dicarboxyl groups to build a compact and densely packed barrier layer around the NPLs, passivating surface defects and preventing the adsorption of water molecules and oxygen onto the surface of CsPbBr 3 NPLs …”