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Perovskite solar cells (PSCs) have attracted extensive attention in the photovoltaic field, with their highest power conversion efficiency (PCE) reaching 26%. However, the commercialization of PSCs is severely hindered by the instability of precursor solutions and the narrow annealing window for perovskite films. Here, 2,3,5‐trichlorobenzaldehyde (3Cl‐BZH) is introduced into the organic salt precursor solution to eliminate excess organic amines through Schiff‐base reactions, avoiding subsequent irreversible amine‐cation reaction of formamidine‐methylammonium (FA‐MA+) and improve the stability of the precursor solution. Meanwhile, the chemical interaction between C═O group of 3Cl‐BZH and formamidinium (FA+) in the perovskite precursor contributes to the slow release of organic ions, which reduces the reaction rate between organic salt and PbI2, retarding the crystallization of perovskite film. The PSCs with a conventional annealing process achieve a champion efficiency of 24.08%, which derives from the defect passivation effect of 3Cl‐BZH. The PSCs with an ultrawide annealing window of 240 h for wet perovskite film in the air still maintain an efficiency of 22.01%. The aging‐resistant precursor and ultrawide annealing window are beneficial for reproducible, efficient, and low‐cost PSCs, which brings great prospects for the commercialization of PSCs. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) based on planar SnO2 (p‐SnO2) demonstrate excellent performance due to the superior properties of SnO2 as electron transporting layer (ETL). However, at present mesoporous SnO2 (m‐SnO2) still lags behind p‐SnO2 due to problems in the fabrication process of m‐SnO2. In this paper, a new strategy for preparing m‐SnO2 ETL is introduced which owns two valuable features: First, it applies a low temperature process to make mesoporous structure, which favors preserving the pristine properties of the raw SnO2 nanocrystals. Second, the degree of porosity and roughness of the m‐SnO2 layer can be well controlled, making it friendly to the following deposition process of PSCs. The performance of the PSCs based on the m‐SnO2 ETL prepared from this strategy shows an obvious improvement which is mainly from the improvement in Jsc and FF, suggesting a higher carrier collection efficiency for the m‐SnO2 ETL. The relevant characterizations including PL, TRPL, EIS, and KPFM confirm that the m‐SnO2 ETL possesses stronger electron extraction capability than the p‐SnO2 ETL. Hence, the proposed strategy can manifest the advantages of m‐SnO2 ETL meanwhile refrain its negative impacts, and thus promote the progress of the m‐SnO2 ETL‐based PSCs. [ABSTRACT FROM AUTHOR]

As-doped p-type ZnO films were grown on GaAs by sputtering and thermal diffusion process. Hall effect measurements showed that the as-grown films were of n-type conductivity and they were converted to p-type behavior after thermal annealing. Moreover, the hole concentration of As-doped p-type ZnO was very impressible to the oxygen ambient applied during the annealing process. In addition, the bonding state of As in the films was investigated by x-ray photoelectron spectroscopy. This study not only demonstrated an effective method for reliable and reproducible p-type ZnO fabrication but also helped to understand the doping mechanism of As-doped ZnO. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have attracted intense research interest in the last few years due to their excellent properties. However, the trap states at grain boundary (GBs) of perovskite films lead to charge recombination and perovskite film decomposition, which deteriorate the stability of PSCs. It has been demonstrated that the GBs passivation is an effective way to eliminate trap states and enhance the stability of PSCs. In this work, ethyl acetate (EA) and chlorobenzene (CB) were used as anti-solvent, mixing with phenyl-C61-butyric acid methyl ester (PC61BM) to replace pure antisolvent CB to control the GBs passivation of perovskite film. Meanwhile, enhanced interfacial hydrophobic characteristic effectively restricted the penetration of moisture. Correspondingly, with optimizing the volume ratio of EA/CB, the power conversion efficiency of PSCs based on CH3NH3PbI3 increased from 14.4 to 16.1% and the stability is greatly improved. This shows the adoption of a mixed solvent for EA and CB contained PC61BM as the solute can be used as an efficient tactic to passivate the surface crystal boundary, improve charge carrier transportation and device performance. [ABSTRACT FROM AUTHOR]

Abstract: The growth of highly lattice-mismatched InAs0.3Sb0.7 films on (100) GaAs substrates by magnetron sputtering has been investigated and even epitaxial InAs0.3Sb0.7 films have been successfully obtained. A strong effect of the growth conditions on the film structure was observed, revealing that there was a growth mechanism transition from three-dimensional nucleation growth to epitaxial layer-by-layer growth mode when increasing the substrate temperature. A qualitative explanation for that transition was proposed and the critical conditions for the epitaxial layer-by-layer growth mode were also discussed. [Copyright &y& Elsevier]