High-performance nanoparticle- enhanced tunnel junctions for photonic devices

We describe GaAs-based tunnel junctions that are compatible with photonic devices, including long-wavelength vertical-cavity surface-emitting lasers and multi-junction solar cells. Tunneling was enhanced with semimetallic ErAs nanoparticles, particularly when grown at reduced substrate temperatures. Additionally, we present the first direct measurement of the quality of III-V layers grown above ErAs nanoparticles. Photoluminescence measurements indicate that III-V material quality does not degrade when grown above ErAs nanoparticles, despite the mismatch in crystal structures. These findings validate these tunnel junctions as attractive candidates for GaAsbased photonic devices.