Recent Progress on Interface Engineering for High‐Performance, Stable Perovskites Solar Cells

Abstract

Rapid progress in the domain of perovskite solar cells (PSCs) has boosted the power conversion efficiency (PCE) of such cells to 25.2%. However, the long‐term stability of a high‐performance PSCs is still the foremost concern that hinders its practical application. The interfaces are considered as the key part that determines the overall device performance and longevity. These interfaces include the intralayer grain boundaries (GBs) inside the perovskites, the interface between perovskites with electron/hole transport layer (ETL/HTL), and the interface of ETL/HTL with top/down contacts. To acquire a deep and detailed understanding of the impacts of interfacial properties, herein, a concise overview of recent interfacial engineering strategies with the aim of minimizing traps, promoting carrier extraction, and improving stability are summarized.

Elimination of Interfacial Lattice Mismatch and Detrimental Reaction by Self‐Assembled Layer Dual‐Passivation for Efficient and Stable Inverted Perovskite Solar Cells

“…[ 6 ] In order to acquire high‐efficiency PVSCs devices, numerous researchers have concentrated on adjusting the chemical composition of perovskite and modifying the charge transporting layers (CTLs), yet the interfacial mismatch between perovskite and CTLs is a non‐negligible issue that dominates the efficiency and stability of corresponding devices. [ 7–11 ] Nickel oxide (NiO x ) nanocrystals as a promising stable hole transporting layer (HTL) in inverted p–i–n PVSCs are less prone to hysteresis and work well with flexible or tandem architectures. [ 12 ] Nevertheless, the PCE of NiO x ‐based inverted devices are usual inferior to the organic regular counterparts owing to the several interfacial issues: i) abundant surface traps and mismatch energy level restrict the charge carrier extraction, causing large energy offset; [ 13 ] ii) the redox reaction between Ni 3+ and A‐site cation salts form a PbI 2 ‐rich hole extraction barrier, leading to severe interfacial destruction; [ 14 ] iii) inconsistent thermal expansion of lattice units in NiO x and perovskite results in tensile strain, prejudicing the microstructure and accelerating the degradation of perovskite.…”

Organic Ammonium Halide Modulators as Effective Strategy for Enhanced Perovskite Photovoltaic Performance

“…Various approaches based on this principle have so far been developed and employed in PSCs. [38][39][40][41][42] Especially ammonium halides have demonstrated a remarkable potential owing to their tunable electro-chemical and optical properties, for instance, their interaction with lead cations, hydrophobicity and optical behavior, as well as low production costs and solution processability. [26,43,44] A general formula for an organic ammonium-based passivation agent can be abbreviated as R-N 1 R 2 R 3 R + X − (Figure 1a), where R and X represent an organic moiety and monovalent halide anion, respectively.…”

Single- or double A-site cations in A3Bi2I9 bismuth perovskites: What is the suitable choice?

“…Efforts have been made to improve the stability via interface engineering, compositional engineering, development of multi-dimensional (2D + 3D) perovskites, etc. [9,[11][12][13]. Among all these approaches, compositional engineering has been at the forefront of research efforts as it not only helps to develop a robust perovskite composition but also helps in tuning its optoelectronic properties [9,14,15].…”