Scientists from the University of Illinois claim to have shown off the first optoelectronically active 3D photonic crystal.
While other scientists have made 3D photonic crystals, they haven’t been able to make units that can direct light but they’re not electronically active. The Illinois team say that its crystal can turn electricity to light, and light to electricity. That could lead to applications including solar cells and lasers.
The scientists made a template of dense tiny spheres and deposited gallium arsenide (GaAs) to fill the holes between the spheres. The GaAs grows as one crystal using epitaxy. After the template has been filled, the researchers removed the spheres, leaving a porous 3D single crystal semiconductor.
The researchers built a working 3D photonic crystal LED. The next target for them is to apply a similar method using different semiconductor materials.
Eric Nelson, a postdoctoral researcher at Harvard University, worked with Professor Paul Braun. Nelson said that the device geometry can be changed to create a unit with whatever properties people want. “It really opens up a whole new area of research into extremely efficient or novel energy devices,” he said. “With our approach to fabrication photonic crystals, there’s a lot of potential to optimise electronic and optical properties simultaneously.”