Crystallization Regulation and Dual‐Defects Healing by Self‐Polymerization of Multifunctional Monomer Additives for Stable and Efficient CsPbBr₃ Perovskite Solar Cells

Abstract

The photovoltaic performance of perovskite solar cells (PSCs) is immensely related to the perovskite film quality, defect states density, and interfacial energy‐level alignment. Herein, a self‐polymeric monomer of N‐(hydroxymethyl) acrylamide (HAM) with CC, CO, and –NH multifunctional groups is introduced in the preparation of a CsPbBr3 film by a two‐step method to regulate the crystallization process and band structure and simultaneously passivate the dual‐ionic defects. The results show that the HAM monomer first undergoes a pre‐polymerization in the CsBr precursor aqueous solution after preheating to retard the crystallization of CsPbBr3, and subsequently a further polymerization occurs during the annealing of the perovskite film to load at grain boundaries and form the CO⋯Pb (Cs) Lewis acid–base coordination and N–H⋯Br hydrogen bonding. Consequently, a large‐grained CsPbBr3 film with low defect density and optimized band structure is fabricated to effectively suppress nonradiative recombination and accelerate carrier extraction and transport, delivering a champion power conversion efficiency of 9.05% for the HAM‐incorporated CsPbBr3 PSCs, which is much higher than 6.50% efficiency for the reference one. Furthermore, the unencapsulated device maintains over 92% of the initial efficiency after 30 days storage in air with 85% relative humidity or at 85 °C, exhibiting superior moisture and thermal durability.

Synergistic passivation with multi-dentate 2,6-pyridinedicarboxylic acid for high-performance perovskite solar cells

“…2(d)), evidencing the hydrogen bonds between -OH and I À . 43,44 XPS analysis of the MAPbI 3 and MAPbI 3 /2,6-PDA films (Fig. S1a, ESI †) was also performed to estimate the interaction between MAPbI 3 and 2,6-PDA.…”

Effect of Yttrium-Incorporated TiO2 Electron Transport Layer on the Photovoltaic Performance of Triple-Cation Perovskite Solar Cells

“…These results were further confirmed by the dependence of V OC and J SC on light intensity. For solar cells, V OC can be calculated by the formula V OC = ε italickT q ln ( I ) + n 0 , of which ε is an ideal factor concerned with the defect-induced nonradiative recombination and k , T , q , n 0 are constants. , Under ideal conditions, the slope would be infinitely close to kT / q . As exhibited in Figure e, the device assembled with TiO 2 ETL shows a larger slope of 2.51 kT / q .…”

Research Progress of Green Solvent in CsPbBr3 Perovskite Solar Cells

“…Third, when using water as the solvent of CsBr, the perovskite films prepared using a two-step spin-coating method will contain many defects due to the high crystallization rate, which will function as nonradiative recombination centers for photogenerated carriers [ 53 ].…”

“…He’s group [ 53 ] added a self-polymeric monomer of N-(hydroxymethyl) acrylamide (HAM) containing C=C, C=O, and -NH multifunctional groups in CsBr aqueous solution to prepare CsPbBr 3 PSCs using a two-step method. The best power conversion efficiency of the cell was 9.05%.…”