Luminescent N-polar (In,Ga)N/GaN quantum wells grown by plasma-assisted molecular beam epitaxy at high temperature

Abstract

N-polar (In,Ga)N/GaN quantum wells prepared on freestanding GaN substrates by plasma-assisted molecular beam epitaxy at conventional growth temperatures of about 650 °C do not exhibit any detectable luminescence even at 10 K. In the present work, we investigate (In,Ga)N/GaN quantum wells grown on Ga- and N-polar GaN substrates at a constant temperature of 730 °C. This exceptionally high temperature results in a vanishing In incorporation for the Ga-polar sample. In contrast, quantum wells with an In content of 20% and abrupt interfaces are formed on N-polar GaN. Moreover, these quantum wells exhibit a spatially homogeneous green luminescence band up to room temperature, but the intensity of this band is observed to strongly quench with temperature. Temperature-dependent photoluminescence transients show that this thermal quenching is related to a high density of nonradiative Shockley-Read-Hall centers with large capture coefficients for electrons and holes.

arXiv comment10 pages, 2 figures, 1 table

References in corpus (4)

• Unraveling the "Green Gap" problem: The role of random alloy fluctuations in InGaN/GaN light emitting diodes
• Atomistic analysis of the impact of alloy and well-width fluctuations on the electronic and optical properties of InGaN/GaN quantum wells
• Comparison of the luminous efficiency of Ga- and N-polar In${}_x$Ga${}_{1-x}$N/In${}_y$Ga${}_{1-y}$N quantum wells grown by plasma-assisted molecular beam epitaxy
• Ga-polar (In,Ga)N/GaN quantum wells vs. N-polar (In,Ga)N quantum disks in GaN nanowires: Comparative analysis of carrier recombination, diffusion, and radiative efficiency

Cited by in corpus (4)

• Polarization control in Nitride Quantum Well Light Emitters Enabled by Bottom Tunnel-junctions
• Excitonic and deep-level emission from N- and Al-polar homoepitaxial AlN grown by molecular beam epitaxy
• Absence of quantum-confined Stark effect in GaN quantum disks embedded in (Al,Ga)N nanowires grown by molecular beam epitaxy
• Interface recombination in Ga- and N-polar GaN/(Al,Ga)N quantum wells grown by molecular beam epitaxy