We report herein the discovery of methylamine (CH3NH2) induced defect-healing (MIDH) of CH3NH3PbI3 perovskite thin films based on their ultrafast (seconds), reversible chemical reaction with CH3NH2 gas at room temperature. The key to this healing behavior is the formation and spreading of an intermediate CH3NH3PbI3⋅xCH3NH2 liquid phase during this unusual perovskite-gas interaction. We demonstrate the versatility and scalability of the MIDH process, and show dramatic enhancement in the performance of perovskite solar cells (PSCs) with MIDH. This study represents a new direction in the formation of defect-free films of hybrid perovskites.

Solution-processed perovskite (PSC) solar cells have achieved extremely high power conversion efficiencies (PCEs) over 20%, but practical application of this photovoltaic technology requires further advancements on both long-term stability and large-area device demonstration. Here, an additive-engineering strategy is developed to realize a facile and convenient fabrication method of large-area uniform perovskite films composed of large crystal size and low density of defects. The high crystalline quality of the perovskite is found to simultaneously enhance the PCE and the durability of PSCs. By using the simple and widely used methylammonium lead iodide (MAPbI ), a certified PCE of 19.19% is achieved for devices with an aperture area of 1.025 cm , and the high-performing devices can sustain over 80% of the initial PCE after 500 h of thermal aging at 85 °C, which are among the best results of MAPbI -based PSCs so far.

We demonstrate the feasibility of a nonsalt-based precursor pair--inorganic HPbI3 solid and organic CH3NH2 gas--for the deposition of uniform CH3NH3PbI3 perovskite thin films. The strong room-temperature solid-gas interaction between HPbI3 and CH3NH2 induces transformative evolution of ultrasmooth, full-coverage perovskite thin films at a rapid rate (in seconds) from nominally processed rough, partial-coverage HPbI3 thin films. The chemical origin of this behavior is elucidated via in situ experiments. Perovskite solar cells, fabricated using MAPbI3 thin films thus deposited, deliver power conversion efficiencies up to 18.2%, attesting to the high quality of the perovskite thin films deposited using this transformative process.

Perovskite solar cells (PSCs) emerging as a promising photovoltaic technology with high efficiency and low manufacturing cost have attracted the attention from all over the world. Both the efficiency and stability of PSCs have increased steadily in recent years, and the research on reducing lead leakage and developing eco-friendly lead-free perovskites pushes forward the commercialization of PSCs step by step. This review summarizes the main progress of PSCs in 2020 and 2021 from the aspects of efficiency, stability, perovskite-based tandem devices, and lead-free PSCs. Moreover, a brief discussion on the development of PSC modules and its challenges toward practical application is provided.

Studies on doping and alloying for the advancement of perovskite solar cells are critically reviewed.

This article reviews 86 studies and uses meta-analytical methods to investigate how perceived corporate social responsibility (CSR) impacts employee attitudes and behaviors and to identify the mediating mechanisms and boundary conditions. An initial review of this body of research finds a multitude of mediators but a limited focus on CSR typology as a potential moderator. Drawing upon social exchange theory, we develop and test two multivariate mediation models to integrate and synthesize three most-studied mediating mechanisms: organizational justice, organizational trust, and organizational identification. Meta-analyses find that while all three mechanisms within the parallel mediation model are equally significant in mediating the effect of perceived CSR on organizational commitment and job satisfaction, organizational identification is superior to organizational justice and organizational trust in mediating the effect of CSR perceptions on organizational citizenship behavior (OCB) and turnover intention. It is also found that although both mediation models adequately represent the accumulated empirical data, the sequential model is statistically superior to the parallel model. Although meta–structural equation modeling analyses reveal minimal differences between the broadly defined internal and external CSR perceptions, significant heterogeneity exists between perceived CSR and the outcome variables. The additional analyses suggest that significant differences exist between more specific stakeholder CSR types. In summary, this article extends our understanding of how employees perceive and respond to CSR through multiple sociopsychological mechanisms in additive and sequential fashions and how such responses could differ depending on the specific stakeholder subgroups targeted by CSR. Theoretical contributions and future research directions are also discussed.

Effective passivation and stabilization of both the inside and interface of a perovskite layer are crucial for perovskite solar cells (PSCs), in terms of efficiency, reproducibility, and stability. Here, the first formamidinium lead iodide (δ-FAPbI ) polymorph passivated and stabilized MAPbI PSCs are reported. This novel MAPbI /δ-FAPbI structure is realized via treating a mixed organic cation MA FA PbI perovskite film with methylamine (MA) gas. In addition to the morphology healing, MA gas can also induce the formation of δ-FAPbI phase within the perovskite film. The in situ formed 1D δ-FAPbI polymorph behaves like an organic scaffold that can passivate the trap state, tunnel contact, and restrict organic-cation diffusion. As a result, the device efficiency is easily boosted to 21%. Furthermore, the stability of the MAPbI /δ-FAPbI film is also obviously improved. This δ-FAPbI phase passivation strategy opens up a new direction of perovskite structure modification for further improving stability without sacrificing efficiency.

The state-of-the-art perovskite solar cells (PSCs) have bandgaps that are invariably larger than 1.45 eV, which limits their theoretically attainable power conversion efficiency. The emergent mixed-(Pb, This article is protected by copyright. All rights reserved.2 Sn) perovskites with bandgaps of 1.2-1.3 eV are ideal for single-junction solar cells according to the Shockley-Queisser limit, and they have the potential to deliver higher PCEs. Nevertheless, the severe chemical activity of Sn(II) in these perovskites makes it extremely challenging to control their physical properties and chemical stability, thereby leading to PSCs with relatively low efficiency and stability. In this work, we have rationally selected the Lewis-adduct -SnF 2 •3FACl -as an additive in the solution-processing of ideal-bandgap halide perovskites (IBHPs), and prepared uniform largegrain perovskite thin films containing continuously functionalized grain boundaries with the stable SnF 2 phase. Such Sn(II)-rich grain-boundary network significantly enhances the physical properties and chemical stability of the IBHP thin films. Based on this approach, PSCs with an ideal bandgap of 1.3 eV are fabricated with promising efficiency of 15.8%, as well as enhanced stability. The concept of Lewis-adduct-mediated grain-boundary functionalization in IBHPs here points to a new chemical route for approaching the Shockley-Queisser limit in future stable PSCs.