Managing Interfacial Defects and Carriers by Synergistic Modulation of Functional Groups and Spatial Conformation for High‐Performance Perovskite Photovoltaics Based on Vacuum Flash Method

Abstract

Interfacial nonradiative recombination loss is a huge barrier to advance the photovoltaic performance. Here, one effective interfacial defect and carrier dynamics management strategy by synergistic modulation of functional groups and spatial conformation of ammonium salt molecules is proposed. The surface treatment with 3‐ammonium propionic acid iodide (3‐APAI) does not form 2D perovskite passivation layer while the propylammonium ions and 5‐aminopentanoic acid hydroiodide post‐treatment lead to the formation of 2D perovskite passivation layers. Due to appropriate alkyl chain length, theoretical and experimental results manifest that COOH and NH3+ groups in 3‐APAI molecules can form coordination bonding with undercoordinated Pb2+ and ionic bonding and hydrogen bonding with octahedron PbI64−, respectively, which makes both groups be simultaneously firmly anchored on the surface of perovskite films. This will strengthen defect passivation effect and improve interfacial carrier transport and transfer. The synergistic effect of functional groups and spatial conformation confers 3‐APAI better defect passivation effect than 2D perovskite layers. The 3‐APAI‐modified device based on vacuum flash technology achieves an alluring peak efficiency of 24.72% (certified 23.68%), which is among highly efficient devices fabricated without antisolvents. Furthermore, the encapsulated 3‐APAI‐modified device degrades by less than 4% after 1400 h of continuous one sun illumination.

Critical role of 1D materials in realizing efficient and stable perovskite solar cells

“…[53][54][55][56][57][58] The structure of 0D materials (nanoparticles) is oen disordered at the GBs of 3D perovskite lms, causing the scattering of free electrons and thereby reducing electron mobility. [59][60][61] 1D perovskites with edge/corner/face-shared [BX 6 ] 4− have higher stability than 3D perovskites due to the linear arrangement of [BX 6 ] 4− in a shoulder-to-shoulder manner and improved skeleton strength of the perovskite lattice, which can protect the 1D perovskite from invading by moisture and oxygen. Meanwhile, the 1D perovskite oen has a preferential orientation, which could improve the crystallization and passivate the defects in GBs, leading to high-quality perovskite lms and accordingly high-performance devices.…”

Minimizing Buried Interface Nonradiative Recombination Losses by Multifunctional Chemical‐Bridging Molecules Enables Efficient Perovskite Solar Cells

“…Metal halide perovskites have drawn substantial attention from researchers involved in solar application research for over a decade, [1][2][3][4][5] owing to their exceptional optoelectronic properties. [6][7][8][9] The widerange applicability of perovskite materials and the varied device architectures endow them an enticing prospect for commercialization.…”

An interdiffusion-controlled nucleation strategy for efficient sequential deposition of perovskite photovoltaics

“…Obtaining perovskite photoactive layers with low defect density and high film morphology quality has been the most critical research direction in the field of perovskite photovoltaics. 1,2 For optimization from the perspective of the perovskite thin film preparation process, the sequential deposition route enabling the controlled growth of perovskite crystals has become one of the most representative and commonly used wet processes in laboratory for fabricating thin films for state-of-the-art perovskite photovoltaics. 3 Precisely, they are usually first deposited from the PbI 2 precursor and post-annealed to eliminate organic solvents (DMF, DMSO, NMP, etc.…”