Multifunctional Molecule Modification toward Efficient Carbon‐Based All‐Inorganic CsPbIBr₂ Perovskite Solar Cells

Abstract

Favorable stability is a big challenge for the commercialization of perovskite solar cells, and all‐inorganic perovskite semiconductors have attracted much attention due to their excellent performance in this field. In reality, the poor stability is mainly due to the high‐density defects in the perovskite films, which provide a channel for charge nonradiative recombination and ion migration. In this work, a multifunctional aminoguanidine hemisulfate (AG HSUL) is introduced into the CsPbIBr2 perovskite layer to achieve defect passivation. Guanidine cations (GA+) can form strong hydrogen bonds with under‐coordinated halogen ions to stabilize the crystal lattice; the nitrogen atom in the amino group can form a complex with the under‐coordinated lead ion; inorganic acids and ions can not only compensate for halogen anion vacancies, but also combine with lead clusters or capped lead ions to reduce defect density. The synergistic effect of anions and cations can effectively passivate the defects, and an energy conversion efficiency of 10.10% is obtained at the optimal concentration of modification. In addition, carbon electrodes are used instead of metal electrodes, which greatly reduces the cost. The results provide a new idea for the development of efficient all‐inorganic CsPbIBr2 perovskite solar cells.

Surface Passivation by Sulfur-Based 2D (TEA)2PbI4 for Stable and Efficient Perovskite Solar Cells

“…Figure a,b shows the device structure and energy band diagram of the components of the PSCs respectively that we adopted in our study. The valence band maximum (VBM) of TEA 2 PbI 4 perovskite was estimated by UPS. − As illustrated in Figure S8, the VBM is 5.48 eV and the conduction band minimum is 3.14 eV that we calculated from VBM and the optical bandgap (2.34 eV). The energy level diagram suggests that energy levels of the 2D perovskite match well with the pristine MAFA (3D) perovskite for facilitation of charge separation.…”

Effective Passivation with Size‐Matched Alkyldiammonium Iodide for High‐Performance Inverted Perovskite Solar Cells

“…3D profile of the BDA group in Figure 2c showed that BDA is mainly anchored on the perovskite surface. [36][37][38][39] The possible reason for this can be attributed to the fact that BDAI 2 assembles on perovskite grains, limiting the inclination of grains during the growth process, and finally forming a (100) oriented dominant film (Figure S6, Supporting Information). With the grain growth, BDAI 2 is finally discharged to the surface of perovskite films.…”

Recent Progress of Carbon‐Based Inorganic Perovskite Solar Cells: From Efficiency to Stability

“…Various types of organic functional additives, such as organic molecules, [121,253,254] organic salts, [255,256] ammonium salts, [215,257] amino acids, [216,217,258] ionic liquids, [72,259] nanomaterials, [260] quantum dots (QDs), [261] and polymers, [23,[262][263][264][265][266][267] have been applied in CsBX 3 and their derivatives. For example, Wang et al incorporated piperazine-1,4-diium iodide (PZDI 2 ) into CsPbI 3 and confirmed the formation of RP perovskite (Figure 11e).…”