Single photon emission from site-controlled InGaN quantum dots up to 90 K

Semiconductor quantum dots (QDs) have diverse quantum photonic applications [1] due to their atomic-like properties, characterized by discrete, optically active energy states. Most work to date has been based on III-As and III-P materials, which face severe limitations in operating temperature due to their small band offsets and exciton binding energies. On the other hand, QDs have been typically fabricated by the Stranski-Krastanow growth which forms dots at random locations and creates large inhomogeneity in size and spectral distribution, making controlled coupling of QDs with cavities or another QD difficult. Site-controlled InGaN QDs can address both issues. [2] Compared to III-V QDs, InGaN can alleviate the operating temperature limitation thanks to its large exciton binding energy. [3] In this paper, we report single photon emission up to 90 K from site-controlled InGaN QDs, the highest temperature to date for site-controlled QDs to our best knowledge.