Soochow University makes new progress in white perovskite LED research

On September 25, the research team of Soochow University published the latest results of perovskite LED research in "Advanced Functional Materials". The team increased the external quantum efficiency of perovskite white light devices by more than 20%.

It is reported that the advantages of all-inorganic blue perovskite LEDs in terms of color purity and stability are believed to be expected to replace blue fluorescent or phosphorescent organic light emitting diodes. However, in multilayer white perovskite LED applications, related problems remain unresolved.

Photo source: advanced functional materials

In response, the Soochow University team designed a new strategy-hybrid perovskite/organic tandem white LED (POTWLED). POTWLED optimizes blue perovskite LED units with the highest external quantum efficiency of 23.9%, and a low color temperature of 2522K. The research data shows the highest efficiency record of perovskite white LEDs and demonstrates the application potential of hybrid stack technology in preparing high-performance perovskite white LED devices.

Photo source: advanced functional materials

This study verified for the first time the feasibility of fabricating white light devices with hybrid laminated perovskite/organic light emitting diodes and promoted the development of perovskite light emitting devices. At the same time, under different voltages, the emission peak position of the perovskite blue light spectrum remains relatively stable, laying the foundation for achieving efficient and stable blue perovskite LEDs.

In this study, the research team solved three major problems of perovskite LEDs through hybrid lamination technology. One is solvent incompatibility in perovskite white light devices, energy transfer of light-emitting units and halogen ion exchange; the other is perovskite LEDs. The problem of emitting a single color; the third is the problem of short life of perovskite-based white light devices.

The research team said that currently, the external quantum efficiency of perovskite white devices remains at around 12%. The team's latest research will exceed 20% for the first time. This technological progress can promote the future application and development of perovskite LEDs in the field of display and lighting devices.

It is worth noting that since the beginning of this year, Soochow University has achieved research results in the field of perovskite LEDs many times.

In April, Suzhou University cooperated with Liaocheng University to make progress in the research of efficient and stable blue perovskite LEDs, reducing the non-radiative recombination rate of blue perovskite LEDs and inhibiting ion migration. The device prepared by the team reached 8.5% External quantum efficiency; In May, Professor Liao Liangsheng of Suzhou University and his collaborators published a high-efficiency near-infrared LED with a peak EQE of 7.7% at the central wavelength of 990 nm.