Interfacial Embedding of Laser‐Manufactured Fluorinated Gold Clusters Enabling Stable Perovskite Solar Cells with Efficiency Over 24%

Abstract

Tackling the interfacial loss in emerged perovskite‐based solar cells (PSCs) to address synchronously the carrier dynamics and the environmental stability, has been of fundamental and viable importance, while technological hurdles remain in not only creating such interfacial mediator, but the subsequent interfacial embedding in the active layer. This article reports a strategy of interfacial embedding of hydrophobic fluorinated‐gold‐clusters (FGCs) for highly efficient and stable PSCs. The p‐type semiconducting feature enables the FGC efficient interfacial mediator to improve the carrier dynamics by reducing the interfacial carrier transfer barrier and boosting the charge extraction at grain boundaries. The hydrophobic tails of the gold clusters and the hydrogen bonding between fluorine groups and perovskite favor the enhancement of environmental stability. Benefiting from these merits, highly efficient formamidinium lead iodide PSCs (champion efficiency up to 24.02%) with enhanced phase stability under varied relative humidity (RH) from 40% to 95%, as well as highly efficient mixed‐cation PSCs with moisture stability (RH of 75%) over 10 000 h are achieved. It is thus inspiring to advance the development of highly efficient and stable PSCs via interfacial embedding laser‐generated additives for improved charge transfer/extraction and environmental stability.

Methodologies for >30% Efficient Perovskite Solar Cells via Enhancement of Voltage and Fill Factor

“…For example, fluorinated gold cluster (FGC) was proposed for interface engineering. [ 40 ] FGC showing a p‐type semiconducting feature could reduce an interfacial carrier transfer barrier and improve charge extraction at GBs. The moisture stability of perovskite films was also improved owing to the hydrophobic tails of the gold clusters and hydrogen bond of fluorine groups with cations in perovskite films.…”

“…[1,2] Up to now, the highest PCE as high as 24.82% was certified with almost pure FAPbI 3 , [15] and high PCEs exceeding 23% were also reported with similar composition. [14,15,31,39,40] Although high PCEs were achieved using FAPbI 3 , phase instability issue is still problematic. As singlecrystal perovskite showed much lower defect densities (10 9 -10 11 cm À3 ) [41,42] and better stability than the polycrystalline films (10 15 -10 17 cm À3 ), [43,44] single-crystal FAPbI 3 films might be a future direction toward higher PCEs.…”

Grain‐Boundaries‐Engineering via Laser Manufactured La‐Doped BaSnO3 Nanocrystals with Tailored Surface States Enabling Perovskite Solar Cells with Efficiency of 23.74%

“…In specific, consideration is given to unsatisfactory defects on sub-10 nm LBSO nanocrystals surface that promote nonradiative recombination, as well as the incapability of ligand-free nanocrystals additives on preventing the perovskite from degradation by external environmental stimuli, an appropriate multifunctional molecule, PFA, is selected to not only passivate its surface defects, but also address the environmental stability of PSCs through manufacturing functionalized LBSO nanocrystals with grafted fluorocarbon chain of PFA upon regulating laser irradiation time and concentration of the PFA in EA. [56] In this work, PFA presents three functions: i) The passivation of surface defects of LBSO nanocrystals by PFA greatly restrains nonradiative recombination; ii) the hydrophobicity of the fluorocarbon chains enhance the moisture resistance of the perovskite films; and iii) the presence of fluorine in the surface carbon-fluorine chain is expected to form hydrogen bonds with organic cations of perovskite, [56,57] which is encouragingly helpful for improvement of the crystallization kinetics of perovskite with fewer defects and suppression of ionic migration that favors for thermal and operational stability, as further evidenced below.…”

A “double-sided tape” modifier bridging the TiO2/perovskite buried interface for efficient and stable all-inorganic perovskite solar cells

“…The power conversion efficiency (PCE) of organic-inorganic hybrid perovskite solar cells (PSCs) has increased sharply to 25.7% in just a few years through the improvements in strategies such as the optimization of perovskite lm quality, interface engineering, additive engineering, strain engineering and so on. [1][2][3][4][5][6][7] Sadly, the intrinsic decomposition of organic-inorganic hybrid perovskite materials in these cells under the attacks of heat, humidity, light and oxygen seriously destroys the long-term operation stability, which has become a bottleneck problem for the industrial application of PSCs. [8][9][10][11][12] To solve this issue, all-inorganic CsPbI x Br 3Àx (x ¼ 0, 1, 2 or 3) perovskites have attracted extensive attention and are recognized as the most promising substitutes owing to their prominent heat tolerance.…”