Enhancing the photo-luminescence stability of CH₃NH₃PbI₃ film with ionic liquids

Abstract

The methylammonium lead triiodide (CH3NH3PbI3)-based perovskite shows a great alluring prospect in areas of solar cells, lasers, photodetectors, and light emitting diodes owing to their excellent optical and electrical advantages. However, it is very sensitive to the surrounding oxygen and moisture, which limits its development seriously. It is urgent to spare no effort to enhance its optical and electrical stability for further application. In this paper, we synthesize the MAPbI3 perovskite film on the glass substrate with/without the ionic liquid (IL) of 1-Butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) by a simple two-step sequential solution method. The additive of BMIMBF4 can improve the quality of crystal structure. Moreover, the photo-luminescence (PL) intensity of MAPbI3 film with BMIMBF4 is much stronger than the pure MAPbI3 film after a week in the air, which is almost ten-fold of the pure one. Meanwhile, under the illumination of 405-nm continuous wave (CW) laser, the fluorescent duration of the MAPbI3 film with BMIMBF4 is approximately 2.75 min, while the pure MAPbI3 film is only about 6 s. In fact, ionic liquid of BMIMBF4 in the perovskite film plays a role of passivation, which prevents the dissolution of MAPbI3 into CH3NH3 and PbI2 and thus enhances the stability of environment. In addition, the ionic liquid of BMIMBF4 possesses high ionic conductivity, which accelerates the electron transport, so it is beneficial for the perovskite film in the areas of solar cells, photodetectors, and lasers. This interesting experiment provides a promising way to develop the perovskite’s further application.

Two-Photon Absorption of FAPbBr3 Perovskite Nanocrystals

“…There is still a way to go for the practical applications, and methods needs to be used to further strengthen the long-term stability, such as the construction of core-shell structure, ion doping, etc. [55][56][57][58]…”

Recent Advances in Quality Strengthening of Perovskite Films by Additive Engineering for Efficient Solar Cells

“…In light of this study, Ma et al incorporated BMIMBF 4 into the perovskite precursor solution as an additive for perovskite materials. [ 65 ] After BMIMBF 4 passivation, the surface of the perovskite film is more uniform and smoother, and the density of grain boundaries became less than that of the film before passivation, which was due to the fact that the ILs in the film promote the growth of grains. It was further discovered that the utilization of BMIMBF 4 led to an enhancement in the chemical stability of the perovskite lattice by effectively occupying the vacant ion (I − or MA + ) sites and fixing the ions through the interaction between ions to prevent the carrier migration from the perovskite lattice, thus improving the carrier recombination rate of the perovskite layer.…”

Could two-dimensional perovskites fundamentally solve the instability of perovskite photovoltaics

“…To promote the commercialization of OIHP solar cell, the profound understanding of the light-induced degradation mechanism is necessary. [20,[79][80][81] The light-induced degradation mechanism of conventional 3D perovskites is a complex dynamic process, accompanied by the photo-generated superoxide O − 2 to promote the deprotonation of methyl-ammonium as well as the migration of the halide ions. Recently, Anaya et al clearly revealed that the electrostatic repulsion of the superoxide O − 2 negatively charge layer on the surface of OIHP created under illumination provides a driving force for halide ions to migrate toward bulk from illuminated areas, and the reaction between O − 2 anions and perovskite causes further degradation by formation of volatile methylamine.…”