Growth of 1D Nanorod Perovskite for Surface Passivation in FAPbI₃ Perovskite Solar Cells

Abstract

The regulation of perovskite crystallization and nanostructure have revolutionized the development of high‐performance perovskite solar cells (PSCs) in recent years. Yet the problem of stably passivating perovskite surface defects remains perplexing. The 1D perovskites possess superior physical properties compared with bulk crystals, such as excellent moisture stability, self‐healing property, and surface defects passivation. Here, 4‐chlorobenzamidine hydrochloride (CBAH) is developed as spacer to form orientationally crystallized nanorod‐like 1D perovskite on the top surface of 3D perovskite for surface passivation of FAPbI3 perovskite. Further structure characterizations indicate the coexistence of 1D–3D hybrid perovskite lattices in nanorod‐like perovskite passivation layer, which regulates the crystallization and morphology effectively and assists in promoting charge extraction, and suppressing charge recombination. As a result, the CBAH treated FAPbI3‐based PSCs exhibit a boosted power conversion efficiency of 21.95%. More importantly, the resultant unencapsulated devices display improved thermal, moisture, and illumination stability, and high reproducibility in terms of device performance. These results indicate the potential of organic halide salts for regulation of perovskite crystallization, offering a promising route of utilizing 1D perovskites nanorods in photovoltaic fields.

Stable FAPbI3 hydrate structure by kinetics negotiation for solar cells

“…14–17 Even worse, the presence of water molecules could accelerate such a transition, which reduced the transition time from several hundred hours to only a few hours in a nitrogen gas atmosphere, causing a significant reduction in the PCE of the device. 18–20…”

Terpyridine-zinc(ii) coordination nanosheets as modulators of perovskite crystallization to enhance solar cell efficiency

“…1 One of the key factors in the fabrication of high-efficiency PSCs is the preparation of highly crystalline perovskites with a more uniform lm morphology and fewer defects in nonradiative recombination. [2][3][4] In particular, the quality of perovskites highly depends on the crystallization process, which in turn is determined by compound factors that reduce the activation energy of crystallization in general. Accordingly, several crystal engineering strategies have been adopted to reduce the activation energy of perovskite nucleation and growth by implanting tailored electron transport layers (ETLs) containing heterogeneous nuclei.…”

Intercalation of Ammonium Cationic Ligands Enabled Grain Surface Passivation in Sequential‐Deposited Perovskite Solar Cells

“…For two‐step sequential‐deposited perovskite films, various precursor additives such as methylammonium chloride, [ 21 ] trimesic acid, [ 22 ] lead thiocyanate, [ 23 ] cesium iodide/bromide, [ 24 ] 4‐ tert ‐butylpyridine, [ 25 ] and biguanide hydrochloride [ 26 ] have been incorporated as a crystallization agent at the precursor stage. More recently, bulky aliphatic/aromatic ammonium cations such as n ‐butylammonium, [ 27 ] n ‐octylammonium, [ 28 ] phenethylammonium, [ 29 ] 4‐chlorobenzamide, [ 30 ] 3‐bromobenzylammonium, [ 31 ] 2‐(methylthio)ethylammonium, [ 32 ] 4‐vinylbenzylammonium, [ 33 ] and guanidinium [ 34 ] have been used for the surface passivation of perovskite films, all of which have produced highly positive outcomes. In some of these studies, surface passivation with bulky ammonium cations has led to the formation of low‐dimensional (2D/quasi‐2D) perovskite phases atop the FAPbI 3 film.…”