Interfacial Defect Passivation Effect of N-Methyl-N-(thien-2-ylmethyl)amine for Highly Effective Perovskite Solar Cells

Abstract

Lead ammonium halide hybrid perovskite solar cells (PSCs) are making unprecedented progress as a favorite in photovoltaic technology. However, nonradiative recombination losses caused by defects on the surface of perovskites impede their development. Thereby, it is very important to mitigate or passivate these defects in perovskite films. Herein, a simple defect passivation strategy was designed using N-methyl-N-(thien-2-ylmethyl)­amine (NMTMA) as a passivator at the interface of the perovskite layer and the spiro-OMeTAD hole transport layer (HTL). The results show that the amine group and the thiophene group on the NMTMA can coordinate with the lead ions on the perovskite layer, which effectively reduces the trap-state density and nonradiative carrier recombination. Typically, 1 mg mL–1 NMTMA-modified device achieves a power conversion efficiency (PCE) of 22.67%, together with improved environmental stability and hysteresis effect. This study provides a typical case for organic functional molecules to passivate defects in PSCs.

Efficient furan-bridged dibenzofulvene-triphenylamine hole transporting materials for perovskite solar cells

“…Therefore, FF-OMeTPA would form a slightly more uniform film on the perovskite layer than FT-OMeTPA, which can be a result of its good molecular accumulation. 50,51 The surface hydrophobicity of the molecules doped on perovskite is determined by water contact angle measurement (Fig. S5, ESI †).…”

3-Ethoxy-4-hydroxybenzadehyde Surface Passivation of Perovskite Films Enables Exceeding 24% Efficiency in Solar Cells

“…Surface passivation refers to introducing a passivator on the surface of perovskite films to interact with defects through electrostatic or chemical action, and so the carrier recombination caused by defects is suppressed. A considerable number of passivators have been developed to passivate the surface defects of perovskite films, for example, halide salts, − polymers, , organic small molecules, − ionic liquids, − fullerene derivatives, , and low-dimensional perovskites. − Organic small molecules have the advantages of good solubility and tunable structures for passivating different kinds of defects and can adapt to a variety of perovskite compositions, which has garnered extensive attention. Choi et al developed an indacenodithieno [3,2-b] thiophene-based small molecule (IDTT-ThCz) to perform surface passivation of perovskite layers.…”