Determination of size dependent carrier capture in InGaN/GaN quantum nanowires by femto-second transient absorption spectroscopy: effect of optical phonon, electron-electron scattering and diffusion.
Nanotechnology
; 30(19): 194003, 2019 May 10.
Article
em En
| MEDLINE
| ID: mdl-30665207
ABSTRACT
Understanding the ultrafast processes corresponding to carrier capture, thermalization and relaxation is essential to design high speed optoelectronic devices. Here, we have investigated a size dependent carrier capture process in InGaN/GaN 20, 50 nm nanowires and quantum well systems. Femto-second transient absorption spectroscopy reveals that the carrier capture is a two-step process. The carriers are captured in the barrier by polar optical phonon (POP) scattering. They further scatter into the active region by electron-electron and POP scatterings. The capture is found to slow down for quantum confined structures. A significant number of carriers are found to disappear from the barrier during the diffusion process. All the experimental observations are explained in a simulation framework depicting various scattering mechanisms.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Nanotechnology
Ano de publicação:
2019
Tipo de documento:
Article