  In recent years, there has been a growing demand for room-temperature visible
single-photon emission from InGaN nanowire-quantum-dots (NWQDs) due to its
potential in developing quantum computing, sensing, and communication
technologies. Despite various approaches explored for growing InGaN quantum
dots on top of nanowires (NWs), achieving the emission of a single photon at
room temperature with sensible efficiency remains a challenge. This challenge
is primarily attributed to difficulties in accomplishing the radial confinement
limit and the inherent giant built-in potential of the NWQD. In this report, we
have employed a novel Plasma Assisted Molecular Beam Epitaxy (PAMBE) growth
approach to reduce the diameter of the QD to the excitonic Bohr radius of
InGaN, thereby achieving strong lateral confinement. Additionally, we have
successfully suppressed the strong built-in potential by reducing the QD
diameter. Toward the end of the report, we have demonstrated single-photon
emission (${\lambda}$ = 561 nm) at room-temperature from the NWQD and measured
the second-order correlation function $g^{2}(0)$ as 0.11, which is notably low
compared to other reported findings. Furthermore, the lifetime of carriers in
the QD is determined to be 775 ps, inferring a high operational speed of the
devices.
