All‐inorganic cesium lead bromide (CsPbBr3) perovskite solar cells have attracted enormous attention owing to their outstanding stability in comparison with organic–inorganic hybrid devices. The greatest weakness for inorganic CsPbBr3 solar cells is their lower power conversion efficiencies, mainly arising from inferior light‐absorbance range and serious charge recombination at interfaces or within perovskite films. To address this issue, the lattice doping of lanthanide ions (Ln3+ = La3+, Ce3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Ho3+, Er3+, Yb3+, and Lu3+) into CsPbBr3 films for all‐inorganic solar cells free of hole‐transporting materials and precious metal electrodes is presented. Arising from the enlarged grain size and prolonged carrier lifetimes upon incorporating Ln3+ ions into perovskite lattice, the performances of these inorganic CsPbBr3 solar cell devices are significantly enhanced, achieving a champion efficiency as high as 10.14% and an ultrahigh open‐circuit voltage of 1.594 V under one sun illumination. Meanwhile, the nearly unchanged efficiency upon persistent attack by 80% RH in air atmosphere over 110 d and enhanced thermal stability at 80 °C over 60 d provide new opportunities of promoting commercialization of all‐inorganic CsPbBr3 perovskite solar cells.

A uniform monolayer of alkanethiol-protected gold nanoparticle arrays with ultrahigh density have been used as microcontact-printable charge-trapping layers for the application in flexible flash memories. The new devices are compared to two reference devices with a floating gate created by thermal evaporation and electrostatic self-assembly, and show a large memory window, long retention times and good endurance properties.

Perovskite lattice distortion induced by residual tensile strain from the thermal expansion mismatch between the electron-transporting layer (ETL) and perovskite film causes a sluggish charge extraction and transfer dynamics in all-inorganic CsPbBr 3 perovskite solar cells (PSCs) because of their higher crystallization temperatures and thermal expansion coefficients. Herein, the interfacial strain is released by fabricating a WS 2 /CsPbBr 3 van der Waals heterostructure owing to their matched crystal lattice structure and the atomically smooth dangling bond-free surface to act as a lubricant between ETL and CsPbBr 3 perovskite. Arising from the strain-released interface and condensed perovskite lattice, the best device achieves an efficiency of 10.65 % with an ultrahigh open-circuit voltage of 1.70 V and significantly improved stability under persistent light irradiation and humidity (80 %) attack over 120 days.

Through fabricating a perovskite/photoactive layer mixed light-harvester, the all-inorganic CsPbBr3 PSC achieved a champion PCE of 10.26% and excellent stability in high humidity or high temperature atmosphere.

The crystal distortion such as lattice strain and defect located at the surfaces and grain boundaries induced by soft perovskite lattice highly determines the charge extraction-transfer dynamics and recombination to cause an inferior efficiency of perovskite solar cells (PSCs). Herein, the authors propose a strategy to significantly reduce the superficial lattice tensile strain by means of incorporating an inorganic 2D Cl-terminated Ti 3 C 2 (Ti 3 C 2 Cl x ) MXene into the bulk and surface of CsPbBr 3 film. Arising from the strong interaction between Cl atoms in Ti 3 C 2 Cl x and the under-coordinated Pb 2+ in CsPbBr 3 lattice, the expanded perovskite lattice is compressed and confined to act as a lattice "tape", in which the Pb-Cl bond plays a role of "glue" and the 2D Ti 3 C 2 immobilizes the lattice. Finally, the defective surface is healed and a champion efficiency as high as 11.08% with an ultrahigh open-circuit voltage up to 1.702 V is achieved on the best all-inorganic CsPbBr 3 PSC, which is so far the highest efficiency record for this kind of PSCs. Furthermore, the unencapsulated device demonstrates nearly unchanged performance under 80% relative humidity over 100 days and 85°C over 30 days.