The preparation of high‐quality perovskite films is important for achieving high‐performance perovskite solar cells (PSCs). The effective balance between solvent and antisolvent is an essential factor for regulating high‐quality perovskite film during the spin‐coating and thermal‐annealing steps. In this work, a greener, nonhalogenated, nontoxic bifunctional (anti)solvent, methyl benzoate (MB), is developed not only as an antisolvent to rapidly generate crystal seeds at the perovskite spin‐coating step, but also as a digestive‐ripening solvent for the perovskite precursors, which can prevent the loss of organic components during the thermal‐annealing stage and effectively suppress the formation of miscellaneous lead halide phases. As a result, this novel bifunctional (anti)solvent is employed in planar n–i–p PSCs for engineering high‐quality perovskite layers and thus achieving a power conversion efficiency up to 22.37% with negligible hysteresis and >1300 h stability. Moreover, due to the high boiling point and low‐volatility characteristic of MB, high‐performance PSCs are achieved reproducibly at different operating temperatures (22–34 °C). Therefore, this developed bifunctional solvent system can provide a promising platform toward globally upscaling and commercializing PSCs in all seasons and regions.

Rapid processing technologies of perovskite solar cells (PSCs) offer an exciting approach to raise the rate of production. Herein, a rapid microwave‐annealing process (MAP) is reported to replace the traditional hotplate annealing process (HAP) and the processing period of perovskite is reduced to less than 1 min. Benefiting from the penetrability and simultaneity of microwave irradiation, the MAP method can effectively eliminate miscellaneous phases and thus achieve >1 µm large‐size crystal grains in perovskite films. These MAP treated perovskite films exhibit pure crystalline phase, long charge‐carrier lifetime, and low defect density, which can substantially improve the PSC efficiency without requiring an additional enhancer/passivation layer. The inverted planar PSCs present enhanced power conversion efficiency from 18.33% (HAP) to 21.59% (MAP) and good stability of >1000 h lifetime without encapsulation under ambient conditions. In addition, MAP can be applied to a large‐size (10 cm × 10 cm) perovskite film fabrication as well as a broader tolerance in environmental temperature and precursor concentration, making it a reliable method for repeatably practical fabrication of perovskite photovoltaics.

Window glazing plays an essential role to modulate indoor light and heat transmission, which is a prospect to save the energy cost in buildings. The latest photovoltachromic technology has been regarded as one of the most ideal solutions, however, to achieve full-frame size (100% active area) and high-contrast ratio (>30% variable in visible wavelength) for smart window applicability is still a challenge. Here we report a photovoltachromic device combining full-transparent perovskite photovoltaic and ion-gel based electrochromic components in a vertical tandem architecture without any intermediated electrode. Most importantly, by accurately adjusting the halide-exchanging period, this photovoltachromic module can realize a high pristine transmittance up to 76%. Moreover, it possesses excellent colour-rendering index to 96, wide contrast ratio (>30%) on average visible transmittance (400-780 nm), and a self-adaptable transmittance adjustment and control indoor brightness and temperature automatically depending on different solar irradiances.

Benefiting from the rapid development on chloride incorporated perovskite materials, nowadays, novel device fabricating techniques have sparked a new vision of ultraviolet photodetectors (UVPDs), which is moving toward higher precision, lower energy consumption, and greater miniaturization. Nevertheless, the natural poor solubility of chloride precursors for perovskites has limited their processability for achieving high‐performance self‐driven photovoltaic‐type UVPDs. Herein, a ball‐milling pretreated single‐source vapor deposition strategy is presented, which can facilely fabricate a pure‐phase CsPbCl3 perovskite film with supermicrometer crystal size and no grain boundaries in the vertical direction. Based on this excellent quality UV harvesting perovskite layer, an optimized self‐driven visible‐blind UVPD exhibits outstanding detection properties, including a superior peak responsivity of 118 mA W−1, a maximum specific detectivity of 6.62 × 1012 Jones, and a wide linear dynamic range of 136 dB, coupled with >1000 h operational durability in air ambient. Most notably, a recorded ultrafast rise/fall response time of 120/820 ns is realized as the fastest responsive perovskite UVPDs to date. In addition, this CsPbCl3 UVPD offers adequate visible‐transparency (>50% average visible transmittance) for a glazing integration by using a transparent back electrode, providing a promising pathway to realize a transparent sensor system for future smart window applications.