Japanese research team overcomes inefficiency problem of traditional gallium nitride red light emission

Recently, research by researchers from Osaka University and Ritsumeikan University in Japan has proven that growing europium-doped gallium nitride (Eu-doped GaN) on a semipolar crystal surface can significantly improve the red light emission performance. This method can selectively promote the formation of efficient europium luminescent centers, making the red light emission intensity more than 3.6 times higher than that of materials grown on traditional polar surfaces.

Gallium nitride materials containing europium (Eu) are considered to be ideal red LED light sources. The internal structure of the europium element is very special. The red light it emits is not only extremely pure in color, but also not prone to color cast. The wavelength is very stable even if the device operates for a long time.

In the past, scientists often grew this red-emitting material on traditional polar crystal planes. However, this method can easily cause the europium element to form many inefficient light-emitting points inside, causing the final red LED to emit darker light.

In this regard, the Japanese research team changed their thinking, changed the angle of crystal growth, and cultivated this material on a tilted semi-polar crystal plane. The experimental results showed that the ineffective structures with extremely low luminous efficiency disappeared, while the number of efficient luminous structures increased.

Through precision instrument analysis, researchers found that this new growth method allows the material to absorb more oxygen during the growth process. The addition of oxygen plays a key "grooming" role, prompting the europium elements to be arranged into an efficient light-emitting structure. In addition, this new material not only performs well under low light, but also maintains stable high brightness even under strong light conditions with increased power, without the common efficiency attenuation problem of traditional LEDs.

This research points out a new way to manufacture high-brightness red LEDs. Professor Shuhei Ichikawa, the senior author of the study, said that the team's research proved that simply changing the growth surface of the crystal can produce extremely efficient light-emitting structures. This is a very promising technical route, and the team will continue to optimize the process and push ultra-high-resolution, wide-color-gamut full-color Micro LED displays into practical applications as soon as possible.