Scientists use thin perovskite films to find new ways to improve the performance of electronic devices

[ Instrument Network Instrument R & D ] What is an electronic device? Today, Xiaobian first takes everyone to understand that an electronic device refers to a device made by using and controlling the laws of electronic movement in a vacuum, gas or solid. Divided into electric vacuum devices, inflatable tube devices and solid-state electronic devices. Used for rectification, amplification, modulation, oscillation, frequency conversion, phase lock, control, and related functions in analog circuits; for sampling, limiting, logic, storage, counting, and delay in digital circuits. The inflatable tube device is mainly used for rectification, voltage stabilization and display. Solid-state electronic devices such as integrated circuits.

It is reported that in order to improve the performance of perovskite electronic devices, scientists have developed a new method that allows researchers to make more efficient and longer-lasting perovskite solar cells, LEDs and photodetectors.

The perovskite organic lead-iodine compound has a suitable band structure, good light absorption performance, and can absorb almost all visible light for photoelectric conversion. It has the characteristics of self-assembly, so the synthesis is simple, and effective thin film deposition can be achieved by a low-temperature and low-cost liquid phase method.

It is reported that the researchers cultivated five kinds of perovskite crystals with different strengths, whose strains range from 0 to -2.4%. In future research, researchers will explore how to use this strain engineering method to discover more new properties and functions of perovskite. They will also work to expand their production processes to produce large single crystal thin films for industrial applications.

"You can use strain engineering as a knob to adjust existing functions and even install new ones in materials," said Sheng Xu, a professor of nanoengineering at the Jacobs School of Engineering at the University of San Diego and senior author of the study. Making a small amount of strain in perovskite is very interesting because it provides a way to make major changes to the material's properties, such as how it conducts, absorbs, and transmits light, or how stable it is.

Some techniques introduce strain into perovskite crystals by heating, but this strain is usually transient or uncontrollable in terms of its strength, which makes these strain-engineered perovskites unusable.

Existing strain engineering technologies are also incompatible with equipment manufacturing processes. Xu and his team solved these problems by carefully cultivating deformed perovskite single crystals. Their technology permanently embeds strain into the structure of the material and allows them to adjust the magnitude of the strain-the greater the lattice deformation, the greater the strain.

In addition, the type of perovskite studied in the study is alpha-formamidinium lead iodide, which has hitherto been used to make the most efficient perovskite solar cells. Researchers grow crystals of materials on a series of perovskite substrates with different compositions and lattice sizes, a process called heteroepitaxial growth.