Reduction of radiative lifetime and slow-timescale spectral diffusion in InGaN polarized single-photon sources

TL;DR

This paper reports on improved growth techniques for a-plane InGaN quantum dots that significantly reduce radiative lifetime and spectral diffusion, enhancing their potential for high-temperature, polarized single-photon applications.

Contribution

The study introduces a quasi-two-temperature growth method for a-plane InGaN QDs that reduces carrier trapping and spectral diffusion, advancing the non-polar InGaN platform.

Findings

~45% shorter radiative lifetime

65% reduction in spectral diffusion

Successful polarized single-photon emission

Abstract

Non-polar (11-20) a-plane quantum dots (QDs) are strong candidates for both > 200 K on-chip ultrafast polarized single-photon generation and the investigation of high temperature semiconductor QD photophysics. In this work, we report progress in the growth of a-plane InGaN QDs with a quasi-two-temperature method, which produces smooth epilayers and significantly reduced carrier trapping sites in the proximity of the QDs. Optical characterization has confirmed the ability of such QDs to emit polarized single photons and we have recorded a ~ 45% shorter average radiative lifetime and 65% reduction in the slow-timescale spectral diffusion compared to previous QDs. This growth method is an important development of the non-polar a-plane InGaN platform, opening up more possibilities in single-photon, lasing, and fundamental investigations.