Princeton University

School of Engineering & Applied Science

Physics, Chemistry and Optimization of Perovskite Light Emitting Diodes

Lianfeng Zhao
Prof. Rand
Engineering Quadrangle B418
Friday, May 3, 2019 - 8:45am to 10:15am


The desire for high color quality, low cost and stable lighting and display technology has driven intense research and development of better light emitting materials and devices. Organic-inorganic hybrid perovskites have demonstrated the potential to develop into a new generation of light emitting diodes (LEDs) that have unique advantages such as high color purity, wide emission wavelength tunability, solution processability, and easy fabrication at low cost. In this work, we focus on understanding the physics, chemistry and processing of perovskite semiconductors, and how best to exploit that understanding to optimize device performance of perovskite LEDs.

In the first part of this work, several important design principles for perovskite LEDs are identified, which include perovskite grain size control, defect passivation, and light outcoupling. Using all these various techniques, it is shown how highly efficient and flexible perovskite LEDs have been achieved. The second major theme of this work involves understanding the stability and degradation mechanisms of perovskite LEDs. The roles of material properties, device structures and operational conditions are approached through extensive in-situ and ex-situ characterization techniques. Finally, we present our outlook on the future development of perovskite optoelectronic devices.