Breakthrough in efficiency of perovskite LEDs

Further advancing LED capabilities, a Purdue group in the Davidson School of Chemical Engineering has discovered that LEDs based on halide perovskites — direct band gap semiconductors — can produce more vivid, colorful and brighter images on the display panels of devices such as cell phones and TVs.

Led by Letian Dou, Charles Davidson Associate Professor of Chemical Engineering, the team has published its work in Nature Communications.

On the downside, perovskite materials are less stable and can degrade quickly. Further, device efficiency has not been fully optimized to compete with conventional LEDs.

“Our work aims to resolve these critical issues,” said Dou, who conceived the idea, supervised the project and provided funding support.

“We achieved efficient and stable deep-red LEDs with a peak external quantum efficiency of 26.3%, which is the highest efficiency for red perovskite LEDs. The stability results are also better than the perovskite LEDs based on similar materials,” Wang said. “In addition, our devices exhibited wide wavelength tunability and improved spectral and phase stability compared with existing perovskite LEDs.”

Fundamentally, these discoveries provide critical insights into the molecular design and crystallization kinetics of low-dimensional perovskite semiconductors, which is critical for light-emitting devices.