IT House May 8 news, according to China University of Science and Technology news, its Yao Hongbin, Fan Fengjia, Lin Yue, Hu Wei team through the light-emitting diode (LED) "film", found the pure red perovskite led performance bottleneck reasons, and successfully prepared a high-performance pure red perovskite led. The relevant research results were published online in the international academic journal Nature on May 7, Beijing time.
▲ Perovskite 3D Heterojunction Suppression led Hollow Hole Leakage Cartoon
According to reports, metal halide perovskite is a new generation of star semiconductor materials. As a luminescent layer material in LEDs, it has the advantages of high carrier mobility, high color purity, and wide color gamut. Pure red light perovskite led asAs one of the three primary colors, the light source has great potential in the future high-definition display field and has bright application prospects. However, there are currently research difficulties such as difficulty in balancing brightness and efficiency. The research team of the University of Science and Technology of China mainly solved the problem of sudden drop in efficiency when the brightness of pure red perovskite LEDs increases.
Electrically excited transient absorption spectroscopy (EETA), a new method independently developed by Fan Fengjia's team to "take pictures" of LEDs, detects electrons (negative charge) and holes (positive charge) inside the LED and found that hole leakage into the electron transport layer is the cause of the performance bottleneck of pure red perovskite LEDs.
Yao Hongbin’s team proposed a new material structure design “Three-dimensional perovskite heterojunction” that effectively suppresses hole leakage. The team inserted organic molecules inside the perovskite lattice, changed the crystal structure of the luminescent layer, and built a "dam" that blocks holes from leaving the luminescent layer - "Wide Bandgap Energy Barrier", which achieves carrier confinement while maintaining high mobility. Professor Yao Hongbin and Hu WeiThe theoretical structure analysis of this innovative design was carried out by Professor Lin Yue, and the material was fully verified by spherical aberration electron microscopy.
The pure red perovskite led created by the team of China University of Science and Technology based on "three-dimensional perovskite heterojunction" has high performance at the international leading level in terms of peak off-quantum efficiency, maximum brightness, efficiency roll-off, etc., demonstrating the huge potential of the three-dimensional perovskite heterojunction material created by the team in the development of efficient, bright and stable perovskite led.
Song Yonghui (PhD), Li Bo (postdoctoral student), Wang Zijian (PhD graduate student) and Tai Xiaolin (PhD graduate student) of the University of Science and Technology of China are the co-lead authors of this paper; Professor Yao Hongbin, Professor Fan Fengjia, Professor Lin Yue and Professor Hu Wei of the University of Science and Technology of China are the co-authors of this paperCorresponding author. This work was supported by the National Natural Science Foundation of China and the Ministry of Science and Technology. The Physical and Chemical Science Experiment Center provided support for characterization equipment such as SEM, PL, UV-vis, and spherical aberration electron microscopy for the development of this project.
IT House attached paper link:
ANNA