New approaches to photoluminescent composite design points to improved heat transport

Photoluminescent composites are central for light conversion in devices such as light-emitting and laser diodes. Such materials, however, are prone to degradation and heat generation due to non-radiative Stokes loss, hampering their optical performance. Reinforcing heat dissipation remains an important challenge for improved devices in the future.

Xie et al. outlined advances in manipulating heat transport of photoluminescent composites, challenges that lie ahead for the field and emerging approaches.

“While most thermal management technologies for LED only focus on cooling the chips, the thermal management of photoluminescent materials haven’t garnered enough attention,” said author Run Hu. “In our paper, we developed the theories to calculate the heat generation of photoluminescent materials and proposed practical solutions to cool these photoluminescent materials.”

At the center of the work is a concept the team developed called package-inside thermal management, in which they construct an “expressway” with high-conductivity particles for cooling photoluminescent materials.

The paper calls for more work on uncovering the thermal transport mechanisms of amorphous, aligned and crystalline polymers such as silicone and epoxy. Additionally, they advocate for continued research into 3D interconnected networks to enhance passive cooling, drawing on ceramics such as boron nitride.

“It is rather challenging to enhance heat dissipation without sacrificing optical performance.” Hu said. “We find transparent hexagonal boron nitride particles can balance these two aspects well.”

Hu and the group look to continue their work in order to one day construct a 3D interconnected filler network in photoluminescent materials, based on thermally conductive but optically transparent fillers.

Source: “Manipulating heat transport of photoluminescent composites in LEDs/LDs,” by Bin Xie, Run Hu, and Xiaobing Luo, Journal of Applied Physics (2021). The article can be accessed at https://doi.org/10.1063/5.0056228 .

This paper is part of the Engineering and Understanding of Thermal Conduction in Materials Collection, learn more here .