Built-in fields in stacked InGaN/GaN quantum dots

✍ Scribed by Schulz, Stefan ;O'Reilly, Eoin P.

• Book ID: 105366028
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 411 KB
• Volume: 208
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.201000915

✦ Synopsis

Abstract

The built‐in potential ϕ~tot~ of an isolated and of three stacked lens‐shaped c‐plane In~0.2~Ga~0.8~N/GaN quantum dots (QDs) is calculated using a surface integral approach. There remains disagreement about the sign of the shear strain piezoelectric coefficient e~15~, with more recent analysis suggesting e~15~ < 0. We show that with e~15~ < 0, the potential ϕ~tot~ changes sign outside an isolated QD, in contrast to the case with e~15~ > 0. This behaviour affects ϕ~tot~ in a system of stacked QDs. For small barrier thicknesses between the QDs, the potential in the central QD is strongly reduced compared to an isolated QD, independent of the sign of e~15~. Using e~15~ < 0 and small barrier thicknesses, the potential in the remaining two QDs is also slightly reduced, while for larger barrier thicknesses almost no reduction is observed.