Issue 14/2022 - Progress in the preparation of inorganic perovskite cells

Recently, the green printing Song Yanlin research group of the Institute of Chemistry of the Chinese Academy of Sciences has made new progress in the preparation of all-inorganic lead perovskite films and photovoltaic cell research, which has improved the photovoltaic performance of the device and improved the stability
of the battery.

The researchers used lead iodide, cesium iodide and dimethylammonium iodide as precursors and prepared cesium triiodolead perovskite film
by vacuum-assisted thermal annealing.
By adjusting the environmental pressure during annealing, balancing the generation and release rate of organic by-products during the transformation of perovskite films, promoting the nucleation and crystallization of perovskites, reducing the density of defect states in the film and improving the carrier lifetime, the photovoltaic performance of the device was significantly improved, the photoelectric conversion efficiency was increased from 17.
26% to 20.
06%, and the stability of the cell was significantly improved
.

Previously, the research group carried out research on the preparation and performance of organic-inorganic hybrid perovskite solar cells, and used organic cation substitution methods to achieve in-situ conversion of one-dimensional to three-dimensional perovskites, obtain large-area and high-quality perovskite films, and significantly improve
the photovoltaic performance of the device.
They also used methylamine gas to liquefy perovskite films, and then controlled the volatilization of methylamine gas, and for the first time realized the formation of large-area perovskite films
composed of millimeter-level single crystal perovskite grains on titanium dioxide substrates.

In recent years, perovskite materials have attracted attention
in photovoltaic and other optoelectronic fields due to their excellent photoelectric properties and solution processing performance.
At present, the highest photoelectric conversion efficiency of organic-inorganic hybrid perovskite solar cells has exceeded about 25%, which is equivalent to the performance of commercial polycrystalline silicon solar cells, and further improving device efficiency and stability is the key to
commercialization of perovskite cells.
Due to the presence of organic cations in organic-inorganic hybrid perovskites, the thermal stability of the thin film is poor, which affects the photovoltaic performance and lifetime
of the device.
It is of great significance
to prepare all-inorganic perovskite batteries by replacing organic cations with inorganic cesium ions.