From Structural Design to Functional Construction: Amine Molecules in High‐Performance Formamidinium‐Based Perovskite Solar Cells

Abstract

Formamidinium (FA) based perovskites are considered as one of the most promising light-absorbing perovskite materials owing to their narrower band gap and better thermal stability compared to conventional methylammonium-based perovskites. Constant improvement by using various additives stimulates the potential application of these perovskites. Amine molecules with different structures have been widely used as typical additives in FA-based perovskite solar cells, and decent performances have been achieved. Thus, a systematic review focusing on structural regulation and functional construction of amines in FA-based perovskites is of significance. Herein, we analyze the construction mechanism of different structural amines on the functional perovskite crystals. The influence of amine molecules on specific perovskite properties including defect conditions, charge transfer, and moisture resistance are evaluated. Finally, we summarize the design rules of amine molecules for the application in high-performance FA-based perovskites and propose directions for the future development of additive molecules.

Surface Re-Engineering of Perovskites with Buckybowls to Boost the Inverted-Type Photovoltaics

“…63 The former is difficult to realize due to the "soft" nature of perovskite materials and the strong builtin electric field within the PSCs, 64 while the latter can be effectively implemented through chemical strategies, including constructing a crystal lattice mismatch within the perovskite framework, inducing a steric impediment effect by incorporating functional materials, and increasing either the number or strength of chemical bonds between additives and perovskites. 65,66 Inspired by the peculiar supramolecular structure comprising the pristine corannulene and iodine molecules, 67 we reasoned that the buckybowl could act as an ion-migration inhibitor, especially for the mobile halogen anions that severely jeopardize the long-term stability of the PSCs. 5 In the mixed perovskite films prepared in this work, iodide migration is also true to the fact.…”

Construction of Efficient and Stable FAPbI3 Perovskite Solar Cells through Bifunctional Ionic Liquid‐Assisted Crystallization and Defect Passivation

“…[ 9,24–27 ] In addition, the FAPbI 3 crystal defects formed during solution process not only result in nonradiative charge recombination but also accelerate phase instability, which seriously restricts the PCE and stability of FAPbI 3 ‐based PSC. [ 28 ] Thus, it makes great sense to explore strategies to fabricate high‐quality and phase‐stable FAPbI 3 films to further promote PSCs for commercial utilization.…”

“…[9,[24][25][26][27] In addition, the FAPbI 3 crystal defects formed during solution process not only result in nonradiative charge recombination but also accelerate phase instability, which seriously restricts the PCE and stability of FAPbI 3based PSC. [28] Thus, it makes great sense to explore strategies to fabricate high-quality and phase-stable FAPbI 3 films to further promote PSCs for commercial utilization. One effective strategy is incorporation of smaller-sized cations and anion, such as Cs þ , MA þ , and Br À , to stabilize α-FAPbI 3 by regulating the Goldschmidt tolerance factor of perovskite.…”

Theoretical investigation of octahedral tilting and bandgap non‐linearity in monolayer Ruddlesden‐Popper A 2 Pb 1‐x Ge x I 4 perovskites

“…The resulting structural design can be investigated theoretically for functional construction of light‐absorbing perovskites layer in solar cell, aiming for high‐performance devices. The design of organic spacer, 2D crystal regulation, moisture resistance, defect condition, and charge‐carrier transport properties can be optimized to achieve highly efficient and robust perovskites solar cells 101 . The search for such materials will give new insights into defect tolerant perovskites that are non‐toxic and stable without encapsulation, thus addressing two key challenges of lead‐halide perovskites.…”