Binary Microcrystal Additives Enabled Antisolvent‐Free Perovskite Solar Cells with High Efficiency and Stability

Abstract

The remarkable progress in PCE can be attributed to excellent photoelectric properties of perovskites, including tunable bandgaps, high absorption coefficients, low exciton binding energies, and long carrier lifetime. [2][3][4][5] To achieve highly efficient and stable PVSCs, formamidinium (FA)-based lead triiodide perovskites have been employed as the prime light absorbers, which possess a relatively narrow bandgap (E g ≈ 1.5 eV) and promising thermal stability. [6][7][8] Consequently, various approaches have been dedicated to manipulate the crystal nucleation and grain growth for achieving high-quality perovskite films. Among these, antisolvent quenching is the most popularly used method for obtaining highly crystalline perovskite films through inducing rapid and uniform nucleation of perovskites, boosting the PCE of both conventional n-i-p and inverted p-i-n PVSCs to go beyond 25%. [9][10][11] However, the device reproductivity is limited by the narrow processing window of antisolvent dripping. [12][13][14] In addition, the commonly used antisolvents (chlorobenzene, toluene, ethyl ether etc) are quite toxic, [15][16][17] which will hinder their application in upscaling production of PVSCs.As a result, there is a strong push for searching antisolvent-free techniques to facilitate swift solvent evaporation and effective tuning of crystallization dynamics of perovskites, Developing a facile method to prepare high-quality perovskite films without using the antisolvent technique is critical for upscaling production of perovskite solar cells (PVSCs). However, the as-prepared formamidinium (FA)-based perovskite films often exhibit poor film quality with high density of defects if antisolvent is not used, limiting the photovoltaic performance and long-term stability of derived PVSCs. Herein, this work adopts presynthesized 3D methylammonium lead chloride (MAPbCl 3 ) and 1D 2-aminobenzothiazole lead iodide (ABTPbI 3 ) microcrystals into self-drying perovskite precursors, which serve as seed crystals to promote nucleation and growth of FAPbI 3 -based perovskites without requiring antisolvent extraction. The combined binary microcrystals facilitate the formation of a dense and pinhole-free perovskite film with a stable perovskite lattice and defect-healed grain boundaries, enabling efficient charge carrier transfer and reduced nonradiative recombination loss. As a result, the best-performing inverted architecture device exhibits a champion power conversion efficiency of 23.27% for small-area devices (0.09 cm 2 ) and 21.52% for large-area devices (1.0 cm 2 ). These values are among the highest efficiencies reported for antisolvent-free PVSCs. Additionally, the unencapsulated device shows enhanced moisture, thermal, and operational stabilities, and maintains 92% of its initial efficiency after being held at the maximum power point for 1000 h.

Minimized Energy Loss at the Buried Interface of p‐i‐n Perovskite Solar Cells via Accelerating Charge Transfer and Forming p–n Homojunction

“…Too much cracks or holes in the perovskite films are harmful for charge separation and transport, which results in severe E loss . [ 33 ] The perovskite films grown on other HTLs exhibit much uniform and compact surface. The crystal sizes of different perovskite films are further investigated and the results are shown in Figure S6, Supporting Information.…”

Seeding Agents in Metal Halide Perovskite Solar Cells: From Material to Mechanism

“…[51] Recently, 3D methylammonium lead chloride (MAPbCl 3 ) combined 1D 2-aminobenzothiazole lead iodide (ABTPbI 3 ) seed crystals could improve the performance of FAPbI 3 -based PSCs and the best PCE was 23.27 %. [52] Perovskite crystals redissolution strategy has developed to fabricate efficient and stable PSCs in a low-cost and reproducible manner. [53] A simple and scalable approach "phaseselective method" was used to fabricate 2D perovskite thin films with homogenous layer thickness (phase purity).…”

“…1D 2‐diethylaminoethylchloride lead iodide (DEAECPbI 3 ) has similar templated effect on α‐FAPbI 3 [51] . Recently, 3D methylammonium lead chloride (MAPbCl 3 ) combined 1D 2‐aminobenzothiazole lead iodide (ABTPbI 3 ) seed crystals could improve the performance of FAPbI 3 ‐based PSCs and the best PCE was 23.27 % [52] …”

Emerging Two-Dimensional Organic Semiconductor-Incorporated Perovskites─A Fascinating Family of Hybrid Electronic Materials

“…Only thin-film properties suggested the formation of this OSiP . Instead of forming the desired layered 2D perovskite structure, the formation of 1D chains or 0D clusters is sometimes inevitable. − With regard to the assembly of 1D versus 2D perovskite structures, Tremblay et al discussed 16 phenyl-ligand-based perovskite crystal structures . They proposed that the formation of either intramolecular hydrogen bonding between the ammonium and substituents on rings or intermolecular hydrogen bonding between neighboring ammoniums drives the structure toward 1D face-shared [PbI 6 ] 4– chains.…”