Opposite carrier dynamics and optical absorption characteristics under external electric field in nonpolar vs. polar InGaN/GaN based quantum heterostructures

Emre Sari, Sedat Nizamoglu, Jung Hun Choi, Seung Jae Lee, Kwang Hyeon Baik, In Hwan Lee, Jong Hyeob Baek, Sung Min Hwang, Hilmi Volkan Demir

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We report on the electric field dependent carrier dynamics and optical absorption in nonpolar a-plane GaN-based quantum heterostructures grown on r-plane sapphire, which are surprisingly observed to be opposite to those polar ones of the same materials system and similar structure grown on c-plane. Confirmed by their time-resolved photoluminescence measurements and numerical analyses, we show that carrier lifetimes increase with increasing external electric field in nonpolar InGaN/GaN heterostructure epitaxy, whereas exactly the opposite occurs for the polar epitaxy. Moreover, we observe blue-shifting absorption spectra with increasing external electric field as a result of reversed quantum confined Stark effect in these polar structures, while we observe red-shifting absorption spectra with increasing external electric field because of standard quantum confined Stark effect in the nonpolar structures. We explain these opposite behaviors of external electric field dependence with the changing overlap of electron and hole wavefunctions in the context of Fermi's golden rule.

Original languageEnglish
Pages (from-to)5442-5450
Number of pages9
JournalOptics Express
Volume19
Issue number6
DOIs
Publication statusPublished - 2011 Mar 14
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Fingerprint Dive into the research topics of 'Opposite carrier dynamics and optical absorption characteristics under external electric field in nonpolar vs. polar InGaN/GaN based quantum heterostructures'. Together they form a unique fingerprint.

  • Cite this