Atomic-Scale Insights into the Dynamics of Growth and Degradation of All-Inorganic Perovskite Nanocrystals

Abstract

An understanding of growth and degradation pathways is significant to solve the problem of the structural instability of all-inorganic perovskite nanocrystals (NCs). However, it is still a great challenge to directly record such dynamic processes with high spatial resolution owing to the existence of complex internal factors even using in situ transmission electron microscopy observation. Here, we employ a glassy matrix to produce CsPbBr3 NCs to ensure that the growth and degradation processes of CsPbBr3 NCs are recorded in the vacuum chamber, which could avoid the influence of the external factors, under electron beam (E-beam) irradiation. In addition, two stages of degradation pathways induced by the E-beam are observed sequentially: (1) a layer-by-layer decomposition and (2) instantaneous vanishing once the radius reaches the critical radius (∼2.3 nm). Indeed, we demonstrated that defects serve as a key flash point that could trigger the structural collapse of CsPbBr3 NCs. Our findings provide critical insights into the general instability issue of all-inorganic perovskite NCs in practical applications.

Effect of ZnO on the crystallization and photoluminescence of CsPbI3 perovskite quantum dots in borosilicate glasses

“…The crystallization process of QDs can be divided into the crystal nucleation process and crystal growth process. The grown kinetics for perovskite QDs has been previously revealed to be dominated by an Ostwald ripening process 18,36 . As the heat treatment temperature and heat treatment duration increase, the size of the QDs becomes larger, resulting in a redshift of the absorption and PL spectra.…”

“…The grown kinetics for perovskite QDs has been previously revealed to be dominated by an Ostwald ripening process. 18,36 As the heat treatment temperature and heat treatment duration increase, the size of the QDs becomes larger, resulting in a redshift of the absorption and PL spectra. With the increase of the heat treatment temperature and heat treatment duration, the concentration of QDs increases, the PL intensity increases first, but as the concentration of QDs further increases, the PL intensity will decrease due to the quenching effect of QDs concentration.…”

Humidity‐Induced Defect‐Healing of Formamidinium‐Based Perovskite Films

“…[40] It was previously reported that defects in perovskite served as key flash points that could trigger structural collapse. [41] We further evaluate the stability of the perovskite films prepared under different conditions. The films are aged at 150 °C and ≈80% RH for the thermal and humidity stability tests, respectively.…”

Glassy Flux Protocol to Confine Lead-Free CsSnX3 Nanocrystals into Transparent Solid Medium

“…The crystal defects in CsSn­(Br 1/2 I 1/2 ) 3 could be discerned from the irregular diffraction spots marked by the circles as shown in the SAED image (Figure c). It is well-known that CsSnX 3 nanocrystals are more unstable than the lead-based perovskites, which could be degraded under the electronic irradiation of TEM . Our results also show that CsSnBr 3 nanocrystals could be destroyed during the long-term elemental mapping process (Figure S6).…”

“…It is well-known that CsSnX 3 nanocrystals are more unstable than the lead-based perovskites, which could be degraded under the electronic irradiation of TEM. 30 Our results also show that CsSnBr 3 nanocrystals could be destroyed during the long-term elemental mapping process (Figure S6). Although stable CsSnX 3 nanocrystals were synthesized through a hot injection method, 17 their lattice structure has not been revealed ever.…”