Haonan Chen

Imagine you have a very bright lamp, but most of the light gets trapped inside. That is what happens in many LEDs today. My research focuses on charge carrier diffusion induced LEDs based on III–V semiconductor nanowires. This project uses a special nanotree structure, where electric charges move through the trunk and light is emitted from the branches. These branches are thinner than the wavelength of the emitted light, which helps the light escape more effectively and makes LEDs brighter and more efficient.

However, these tiny nanowires have a very large surface-to-volume ratio, which means the surface plays a key role in how they work. At the same time, many defects exist on the surface, leading to non-radiative recombination, where electrons and holes are trapped by these surface defects instead of recombining to emit light. As a result, energy is lost as heat rather than light. Therefore, my research also includes surface passivation, which involves finding protective coatings that can reduce this loss, allowing the nanotrees to emit light more efficiently.

The goal of my research is to improve the luminous efficiency of nanowire LEDs through structural innovation and surface passivation. Such advances can make lighting and display technologies more energy-efficient, reduce global electricity use, and support the transition toward a cleaner and more sustainable society.