Brominated PEAI as Multi‐Functional Passivator for High‐Efficiency Perovskite Solar Cell

Abstract

The interfaces of perovskite solar cells (PSCs) are well known to be rich in deep‐level carrier traps, which serve as non‐radiative recombination centers and limit the open‐circuit voltage (Voc) and power conversion efficiency (PCE) of PSCs. Defect chemistry and surface passivators have been researched extensively and mainly focused on the neutralization of uncoordinated lead or anion defects. Herein, a novel brominated passivator 2‐bromophenethylammonium iodide (2‐Br‐PEAI) is introduced for a multi‐functional passivation effect at the perovskite interface. The brominated species readily form 2D perovskite on top of the 3D perovskite and multi‐interact with the 3D perovskite surface. Apart from the halide vacancy filling and anion bonding ability, the Br atoms on the benzene ring can interact with the FA cations via strong hydrogen bonding N‐H ⋯ Br and interact with the [PbI6]4− inorganic framework. The interface defects in the PSCs are well passivated, minimizing non‐radiative recombination and enhancing device performance. As a result, a champion PCE of 24.22% was achieved with high Voc and fill factor. In addition, modified devices also showed enhanced operational stability (retention of >95% initial PCE after 400 h) and humidity resistance (>90% initial PCE maintained after 1500 h under ~50% RH).

Multifunctional succinate additive for flexible perovskite solar cells with more than 23% power-conversion efficiency

“…To investigate the effect of the MS additives, FAPbI 3 perovskite thin films were fabricated by a conventional sequential deposition method as previously reported. 24 , 25 The acquired perovskite thin films are denoted “control” and “MS-perovskite” for the films without and with MS additive (in PbI 2 solution), respectively. The surface scanning electron microscopy images of the control and MS-perovskite film morphologies are shown in Figures 2 A and 2B.…”

A bioinspired flexible neuromuscular system based thermal-annealing-free perovskite with passivation

“…Peaks at 136.1 and 141 eV disappears after treatment with PEAI; this result (Supplementary Fig. 5g ) indicates that undercoordinated Pb 2+ interacts with I – in PEAI to passivate the defects efficiently 21 , 34 Also, the I 3d peak increases by the passivation (Supplementary Fig. 5h ), indicating the presence of abundant iodide on the perovskite surface and that the iodine vacancy can be filled.…”

“…The undercoordinated Pb 2+ can coordinate with the I – anion of PEAI to fill the iodine vacancy. The –NH 3 + group of PEAI can bind with I – of PVK to occupy the cation vacancy, and thereby passivate defects and suppress ion migration in the bulk film 34 . It reduces the number of defects available for ions migration (Supplementary Fig.…”

Double Layer Composite Electrode Strategy for Efficient Perovskite Solar Cells with Excellent Reverse-Bias Stability

“…Another UV-ozone was done before depositing perovskite films. The perovskite films were fabricated by typical two-step method according to our former report [ 27 ]. Subsequently, a thin layer of hole transporting film was deposited by spin coating spiro-OMeTAD solution.…”