The microstructure, local indium composition and photoluminescence in green-emitting InGaN/GaN quantum wells

N Chery; T H Ngo; M P Chauvat; B Damilano; A Courville; P DE Mierry; T Grieb; T Mehrtens; F F Krause; K Müller-Caspary; M Schowalter; B Gil; A Rosenauer; P Ruterana

doi:10.1111/jmi.12657

The microstructure, local indium composition and photoluminescence in green-emitting InGaN/GaN quantum wells

J Microsc. 2017 Dec;268(3):305-312. doi: 10.1111/jmi.12657. Epub 2017 Oct 11.

Authors

N Chery¹, T H Ngo², M P Chauvat¹, B Damilano³, A Courville³, P DE Mierry³, T Grieb⁴, T Mehrtens⁴, F F Krause⁴, K Müller-Caspary⁴, M Schowalter⁴, B Gil², A Rosenauer⁴, P Ruterana¹

Affiliations

¹ CIMAP, 6 Boulevard du Maréchal Juin, Caen, France.
² Laboratoire Charles Coulomb, Batiment 21, Campus Triolet, Université de Montpellier, Montpellier, France.
³ Université Côte d'Azur, CRHEA, CNRS, France.
⁴ Institut für Festkörperphysik, Universität Bremen, Otto-Hahn-Allee 1, Bremen, Germany.

PMID: 29023712
DOI: 10.1111/jmi.12657

Abstract

In this work, we analyse the microstructure and local chemical composition of green-emitting In_x Ga_1-_x N/GaN quantum well (QW) heterostructures in correlation with their emission properties. Two samples of high structural quality grown by metalorganic vapour phase epitaxy (MOVPE) with a nominal composition of x = 0.15 and 0.18 indium are discussed. The local indium composition is quantitatively evaluated by comparing scanning transmission electron microscopy (STEM) images to simulations and the local indium concentration is extracted from intensity measurements. The calculations point out that the measured indium fluctuations may be correlated to the large width and intensity decrease of the PL emission peak.

Keywords: III-nitrides semiconductors; analytical STEM; green LEDs; quantum wells; thin films.