Bright room temperature near-infrared single-photon emission from single point defects in the AlGaN film

Abstract

Near-infrared (NIR) single-photon source plays a key role in a wide range of applications in quantum technology. In particular, in quantum communication, the NIR wavelength operation perfectly matches the relatively low-attenuation transmission window of the optical fiber, which attracts more and more research interest. Here, we report the room temperature single-photon emission from single point defects in the aluminum gallium nitride (AlGaN) film. The obtained single-photon emission covers from 720 to 930 nm and exhibits highly linear polarization and high photon brightness. This may provide a platform for future integrated on-chip quantum photonic devices.

Deciphering the photophysical properties of near-infrared quantum emitters in AlGaN films by transition dynamics

“…The calculated ZPL and ZPL values corresponding to the energy of ZPL from metastable state 3 and excited state 2 to ground state 1 are 1.04 eV (1170 nm) and 1.46 eV (849 nm), respectively. The calculated ZPL value and the experimental value of 1.41 eV (874 nm) 32 are in excellent agreement and the deviation is less than 0.05 eV. This deviation may be attributed to the structural strains and the small component difference as well as the "unphysical" spreading of the polarization charge and the presence of the neutralizing background, and it would decrease as the size of the supercell increases.…”

“…It is generally believed that the YL is caused by the transition from the conduction band or a shallow donor to the deep energy level and should be related to structural defects. 32 The z -axis in Fig. 3(b) corresponds to the absolute z -axis piezo position of the scanner.…”

“…In the previous work, the antibunching fit parameter λ 1 is obtained, 32 and λ 1 = r ′ 12 + r ′ 21 . By linearly fitting λ 1 as a function of the excitation power, we can get the values of r ′ 12 and r ′ 21 ; r ′ 21 = 0.36 ns −1 , and τ = 2.7 ns.…”

“…A more detailed description of the technique can be found in our previous work in ref. 32. The quantum emitters of point defects in the AlGaN film are randomly distributed in the spectral range from 720 nm to 930 nm.…”

“…Defect-related single-photon emission in AlGaN films has been reported in our previous work. 32 The quantum emitter of a single defect in an AlGaN film is bright, linearly polarized and can emit light from 720 nm to 930 nm in the near-infrared spectral range at RT. These advantages make single-point defects in AlGaN films attractive for a variety of applications, especially, quantum information.…”