posted on 2024-02-22, 22:04authored byHao Wang, Zhentao Du, Xue Jiang, Sheng Cao, Bingsuo Zou, Jinju Zheng, Jialong Zhao
Recently,
photodetectors based on perovskite nanoplatelets (NPLs)
have attracted considerable attention in the visible spectral region
owing to their large absorption cross-section, high exciton binding
energy, excellent charge transfer properties, and appropriate flexibility.
However, their stability and performance are still challenging for
perovskite NPL photodetectors. Here, a surface engineering strategy
to enhance the optical stability of blue-light CsPbBr3 NPLs
by acetylenedicarboxylic acid (ATDA) treatment has been developed.
ATDA has strong binding capacity and a short chain length, which can
effectively passivate defects and significantly improve the photoluminescence
quantum efficiency, stability, and carrier mobility of NPLs. As a
result, ATDA-treated CsPbBr3 NPLs exhibit improved optical
properties in both solutions and films. The NPL solution maintains
high PL performance even after being heated at 80 °C for 2 h,
and the NPL film remains nondegradable after 4 h of exposure to ultraviolet
irradiation. Especially, photodetectors based on the treated CsPbBr3 NPL films demonstrate exceptional performance, especially
when the detectivity approaches up to 9.36 × 1012 Jones,
which can be comparable to the best CsPbBr3 NPL photodetectors
ever reported. More importantly, the assembled devices demonstrated
high stability (stored in an air environment for more than 30 days),
significantly exceeding that of untreated NPLs.