Grain Boundary and Interface Passivation with Core–Shell Au@CdS Nanospheres for High‐Efficiency Perovskite Solar Cells

Abstract

The plasmonic characteristic of core–shell nanomaterials can effectively improve exciton‐generation/dissociation and carrier‐transfer/collection. In this work, a new strategy based on core–shell Au@CdS nanospheres is introduced to passivate perovskite grain boundaries (GBs) and the perovskite/hole transport layer interface via an antisolvent process. These core–shell Au@CdS nanoparticles can trigger heterogeneous nucleation of the perovskite precursor for high‐quality perovskite films through the formation of the intermediate Au@CdS–PbI2 adduct, which can lower the valence band maximum of the 2,2,7,7‐tetrakis(N,N‐di‐p‐methoxyphenyl‐amine)9,9‐spirobifluorene (Spiro‐OMeTAD) for a more favorable energy alignment with the perovskite material. With the help of the localized surface plasmon resonance effect of Au@CdS, holes can easily overcome the barrier at the perovskite/Spiro‐OMeTAD interface (or GBs) through the bridge of the intermediate Au@CdS–PbI2, avoiding the carrier accumulation, and suppress the carrier trap recombination at the Spiro‐OMeTAD/perovskite interface. Consequently, the Au@CdS‐based perovskite solar cell device achieves a high efficiency of over 21%, with excellent stability of ≈90% retention of initial power conversion efficiencies after 45 days storage in dry air.

Perovskite Passivation Strategies for Efficient and Stable Solar Cells

“…Reproduced with permission. [ 147 ] Copyright 2020, Wiley‐VCH. d) PCE output at the maximum power point (0.90 V).…”

“…Similarly, Qin et al reported a simple and effective antisolvent engineering method. [ 147 ] A small amount of core‐shell Au@CdS noble metal nanoparticles (NPs) are dispersed in chlorobenzene (CB) which is the antisolvent. Most Au@CdS NPs are deposited in low‐lying areas of the GB.…”

Latest Novelties on Plasmonic and Non-Plasmonic Nanomaterials for SERS Sensing

“…The strong development of plasmonic nanomaterials for various applications such as photovoltaics [ 1 , 2 , 3 , 4 ], optical devices [ 5 , 6 , 7 , 8 , 9 , 10 ], and biochemical sensors [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ] has taken place over these last ten years. The plasmonic nanostructures can also enable the detection of phase transitions under high-pressure conditions [ 18 ], the luminescence upconversion enhancement [ 19 , 20 ], and the optical tuning of photoluminescence [ 21 ] and upconversion luminescence [ 22 ].…”

Diethylammonium Iodide Assisted Grain Growth with Sub‐Grain Cluster to Passivate Grain Boundary for CH3NH3PbI3 Perovskite Solar Cells

“…[ 3,7–9 ] The doping and modification with additive can affect the crystallization, thereby passivate the defects in the bulk or at GBs/surface of perovskite. [ 10 ] At present, inert molecules, [ 11 ] small molecules, [ 12,13 ] carbon nanotubes, [ 14 ] graphene‐quantum‐dots, [ 15 ] core–shell nanomaterials, [ 16 ] and polymers [ 17 ] have been used to passivate the interface defect of perovskite films. [ 2 ] Some organics have been adopted as additives to stabilize the perovskite precursor solution and then form the intermediate adducts with Pb 2+ during perovskite crystal formation.…”