Time-resolved and time-integrated photoluminescence studies of coupled asymmetric GaN quantum discs embedded in AlGaN barriers

Abstract

We have investigated exciton dynamics in asymmetric GaN quantum discs embedded in AlGaN barriers with an Al content of 50% using time-integrated and time-resolved micro-photoluminescence measurements. Emission from the quantum discs emerges at lower energy than that from the GaN nanocolumns, which suggests that GaN quantum discs are strongly affected by the built-in electric field. The lifetimes of localized excitons in quantum discs were obtained. Nonlinear emission from quantum discs under high excitation power was attributed to tunneling of carriers to larger discs from smaller discs.

Plasmon Enhanced Raman from Ag Nanopatterns Made Using Periodically Poled Lithium Niobate and Periodically Proton Exchanged Template Methods

“…This approach has been applied to produce a wide range of nanomaterials, including low dimensional quantum dots and quantum wires [3][4][5]. A main focus on nanopattern research has centred on assembling pre-defined and pre-synthesized tubes and wires with theoretically predicted properties into a technologically feasible environment.…”

Two-Photon Excitation of Asymmetric GaN/AlGaN Quantum Discs

“…Details of the apparatus used for TI-PL and TR-PL measurements can be found in our earlier work [5]. The only changes being that excitation was performed at 415 nm for TPA.…”

Characterization of Tunneling and Free-Carrier Screening in Coupled Asymmetric GaN/AlGaN Quantum Discs

“…Using a combination of time-resolved (TR-) and timeintegrated (TI-) photoluminescence (PL) spectroscopy and multi-band k.p computational modeling with nextnano 3 [3], we have performed a systematic study of carrier tunneling and free-carrier screening in coupled asymmetric GaN Q-discs separated by AlGaN barriers. Carrier tunneling in such structures has been suggested previously [4] and could play an important role in future devices.…”