Thermally Evaporated Metal Halide Perovskites and Their Analogues: Film Fabrication, Applications and Beyond

Metal halide perovskites emerge as promising semiconductors for optoelectronic devices due to ease of fabrication, attractive photophysical properties, their low cost, highly tunable material properties, and high performance. High-quality thin films of metal halide perovskites are the basis of most of these applications including solar cells, light-emitting diodes, photodetectors, and electronic memristors. A typical fabrication method for perovskite thin films is the solution method, which has several limitations in device reproducibility, adverse environmental impact, and utilization of raw materials. Thermal evaporation holds great promise in addressing these bottlenecks in fabricating high-quality halide perovskite thin films. It also has high compatibility with mass-production platforms that are well-established in industries. This review first introduces the basics of the thermal evaporation method with a particular focus on the critical parameters influencing the thin film deposition. The research progress of the fabrication of metal halide perovskite thin films is further summarized by different thermal evaporation approaches and their applications in solar cells and other optoelectronic devices. Finally, research challenges and future opportunities for both fundamental research and commercialization are discussed.

Toward All Room-Temperature, Solution-Processed, High-Performance Planar Perovskite Solar Cells: A New Scheme of Pyridine-Promoted Perovskite Formation

A new, all room-temperature solution process is developed to fabricate efficient, low-cost, and stable perovskite solar cells (PVSCs). The PVSCs show high efficiency of 17.10% and 14.19%, with no hysteresis on rigid and flexible substrates, respectively, which are the best efficiencies reported to date for PVSCs fabricated by room-temperature solution-processed techniques. The flexible PVSCs show a remarkable power-per-weight of 23.26 W g^-1 .

Cadmium-doped flexible perovskite solar cells with a low-cost and low-temperature-processed CdS electron transport layer

Hybrid perovskite solar cells (PSCs) are promising candidates in exploring high performance flexible photovoltaics, where a low-temperature-processed metal oxide electron transfer layer (ETL) is highly preferable.

Rapid, stable and self-powered perovskite detectors via a fast chemical vapor deposition process

Organometal halide perovskite materials are outstanding candidates not only for solar cells but also for photo-detection.

Pinhole-Free Perovskite Films by Methylamine Iodide Solution-Assisted Repair for High-Efficiency Photovoltaics under Ambient Conditions

In this study, we demonstrate a simple strategy for obtaining pinhole-free, homogeneous, well-crystallized perovskite films under ambient conditions. The preparation of perovskite film with high light-harvesting efficiency and long carrier lifetime is verified. By applying this film in TiO₂-based perovskite solar cells (PVSCs), we achieved a high power-conversion efficiency (PCE) of 13.07%, which is doubled with respect to that of the PVSC not subjected to the same improvement procedure (6.54%). High open-circuit photovoltage, photocurrent density, and fill factor are the main contributions to the high PCE that results from low trap density and high recombination resistance of the resultant perovskite films. This work paves a new means for fabricating high-performance perovskite films and PVSC devices in an ambient atmosphere.

Efficient All-Vacuum Deposited Perovskite Solar Cells by Controlling Reagent Partial Pressure in High Vacuum

All-vacuum-deposited perovskite solar cells produced by controlling reagent partial pressure in high vacuum with newly developed multi-layer electron and hole transporting structures show outstanding power conversion efficiency of 17.6% and smooth, pinhole-free, micrometer-sized perovskite crystal grains.

High quality perovskite films fabricated from Lewis acid–base adduct through molecular exchange

High quality CH₃NH₃PbI₃ perovskite films without residual PbI₂ are fabricated from the Lewis adduct of PbI₂·xDMF through molecular exchange. The photovoltaic performances of the perovskite solar cells are thus improved significantly.