Tailoring the Interface with a Multifunctional Ligand for Highly Efficient and Stable FAPbI₃ Perovskite Solar Cells and Modules

Abstract

Perovskite solar cells (PeSCs) using FAPbI 3 perovskite films often exhibit unfavorable phase transitions and defect-induced nonradiative interfacial recombination, resulting in considerable energy loss and impairing the performance of PeSCs in terms of efficiency, stability, and hysteresis. In this work, a facile interface engineering strategy to control the surface structure and energy-level alignment of perovskite films by tailoring the interface between the FAPbI 3 film and hole-transporting layer using 4-hydroxypicolinic acid (4HPA) is reported. According to density functional theory studies, 4HPA has prominent electron delocalization distribution properties that enable it to anchor to the perovskite film surface and facilitate charge transfer at the interface. By enabling multiple bonding interactions with the perovskite layer, including hydrogen bonds, Pb-O, and Pb-N dative bonds, 4HPA passivation significantly reduces the trap density and efficiently suppresses nonradiative recombination. The obtained perovskite films exhibit superior optoelectronic properties with improved crystallinity, pure 𝜶-phase FAPbI 3 , and favorable energy band bending. Following this strategy, 4HPA post-treatment PeSCs achieve a champion power conversion efficiency of 23.28% in 0.12 cm 2 cells and 19.26% in 36 cm 2 modules with excellent environmental and thermal stabilities.

Designing a Novel Hole-Transporting Layer for FAPbI3-Based Perovskite Solar Cells

“…Solar power consumption in the human community has continuously increased over the years, and its significance cannot be overemphasized. − Because of their unique photoelectric features, low cost, and simple manufacturing technique, organometallic perovskites (PVSKs) are quickly emerging as one of the most promising semiconductors for photovoltaic cells. − During the last 10 years, the perovskite solar cells (PSCs) have been able to improve their efficiencies from 3.8% to a verified value of 26%. , Despite substantial breakthroughs, large-scale fabrication of efficient PSCs remains the major hurdle for the practical implementation of perovskites. − Because the most commonly investigated CH 3 NH 3 PbI 3 PVSK suffers from both poor thermal stability (as a result of inherent phase transformation or degradation pathways) and an unfavorable bandgap of 1.58 eV, researchers have looked into alternative PVSKs with various chemical compositions. − Among different types of PVSK semiconductors, formamidinium lead triiodide (FAPbI 3 ) stands out as a result of its expanded absorption edge that reaches the near-infrared region at approximately 840 nm. Additionally, it possesses a bandgap that is suitable and close to the optimal value for a single-junction photovoltaic, as determined by the Shockley–Queisser limit calculations. − These characteristics imply the significant interest of FAPbI 3 in potential breakthroughs in the field of solar cell technology. , Jeong et al reported defect engineering using the pseudohalide anion (HCOO – ) to passivate anion vacancy defects in the FAPbI 3 film and to improve the crystallinity of the film. The champion PSC attained a verified power conversion efficiency (PCE) of 25.2% .…”

Cyclen molecule manipulation for efficient and stable perovskite solar cells

“…Molecule regulation is often used to manipulate Pb-related defects in a perovskite with functional O, S, and P atoms to donate the lone pair of electrons to Pb 2+ ions. 18–22 As a typical molecule, crown ether has been recognized as modifiers or stabilizers in PSCs with a unique ring structure and abundant oxygen chelating with Pb 2+ ions 23–28 to improve the efficiency and stability. Despite the enhancement by crown ethers, most of the devices still suffer from large V oc deficit and unsatisfactory PCE values.…”

Surface pre-sacrifice behavior of thiourea-based 2D perovskites for high-performance perovskite solar cells

“…Interface modification strategies are currently one of the most widely studied and effective methods to reduce the defect density inside the PSCs. 16,17 Various types of passivating molecules with different chemical structures have been designed to target different types of defects at the interface, such as 4-hydroxypicolinic acid (4HPA), 18 N -(2-pyridyl)pivalamide (NPP), 19 self-crosslinked fluorosilicone polymer gel, 20 octylamine (OA) functionalized with sulfanilic acid (OAS), p -toluenesulfonic acid (OAT), camphorsulfonic acid (OAC), 21 and so on. However, due to the singularity of organic passivation molecules, improvements in both efficiency and stability remain limited.…”