Research on the air stability of perovskite solar cells (PSCs) has attracted great attention in the field of photovoltaics. Although device based on lead halide perovskites showing outstanding efficiency, commercialization...

A titanium dioxide (TiO 2 ) compact film is a widely used electron transport layer (ETL) for n–i–p planar perovskite solar cells (PSCs). However, TiO 2 sufferers from poor electrical conductivity, leading to high energy loss at the perovskite/ETL/transparent conductive oxide interface. Doping the TiO 2 film with alkali- and transition-metal elements is an effective way to improve its electrical conductivity. The conventional method to prepare these metal-doped TiO 2 films commonly requires time-consuming furnace treatments at 450–600 °C for 30 min to 3 h. Herein, a rapid one-step laser treatment is developed to enable doping of tantalum (Ta) in TiO 2 (Ta-TiO 2 ) and to simultaneously induce the crystallization of TiO 2 films from its amorphous precursor to an anatase phase. The PSCs based on the Ta-TiO 2 films treated with the optimized fiber laser (1070 nm) processing parameters (21 s with a peak processing temperature of 800–850 °C) show enhanced photovoltaic performance in comparison to that of the device fabricated using furnace-treated films at 500 °C for 30 min. The ambient-processed planar PSCs fabricated under high relative humidity (RH) of 50–70% display power conversion efficiencies (PCEs) of 18.34% and 16.04% for devices based on Cs 0.1 FA 0.9 PbI 3 and CH 3 NH 3 PbI 3 absorbers, respectively. These results are due to the improved physical and chemical properties of the Ta-TiO 2 films treated by the optimal laser process in comparison to those for the furnace process. The laser process is rapid, simple, and potentially scalable to produce metal-doped TiO 2 films for efficient PSCs.

A combination of KBr modification and laser processing is utilized to prepare SnO2 films for rigid and flexible perovskite solar cells (PSCs). The KBr modification effectively passivates the defects at the interface between SnO2 and perovskite as well as grain boundaries of the perovskite film. A power conversion efficiency (PCE) of 20.14% is achieved with the KBr‐modified SnO2 for the rigid PSCs fabricated under a relative humidity of around 65–75%, compared to the pristine SnO2 films with a PCE of 18.66%. Then, a picosecond ultraviolet laser is employed to process KBr‐modified SnO2 films on flexible substrates with a rapid scanning rate of 100 mm s−1. The laser process improves the PCEs and durability of the PSCs. The flexible PSCs fabricated by the laser remain over 80% of their initial PCEs after 1000 bending cycles, higher than those fabricated by the hot plate showing 40% of their initial PCEs after the same bending cycles.

A passivation treatment is proposed that improves perovskite photovoltaic device performance and stability to annealing in dry environments. A rationale is presented for the observed loss of stability on heating in wet environments.

This article presents a novel metrological calibration method for trace chromium(VI) analyzer. The study identifies all factors that affect the accuracy of chromium(VI) analyzers, and proposes calibration items and method for the analyzer based on its working principle. The calibration items include pump set flow error and pump flow stability, set temperature error and temperature control stability of column oven, baseline noise and drift, minimum detection concentration, linear range, and qualitative and quantitative repeatability. Experimental results shows that, the presented method can meet the requirements for the metrological performance evaluation of chromium(VI) analyzer. The calibration method is scientific and feasible.