Effects of biaxial strain and chemical ordering on the band gap of InGaN

Journal Article · Mon Jan 08 04:00:00 EST 2001 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.1338490· OSTI ID:40205260

Wright, A F; Leung, K; van Schilfgaarde, M

We have performed first-principles calculations to examine the effects of biaxial strain and chemical ordering on the band gap of wurtzite In{sub x}Ga{sub 1-x}N in the range 0{<=}x{le}0.5. Our results for random unstrained alloys are in good agreement with theoretical estimates and measurements on unstrained zinc-blende alloys, but are in poor agreement with recent measurements on strained wurtzite alloys which display significantly lower band gaps. Biaxial strain is found to have a nonlinear effect on alloy band gaps, increasing them for x<0.25 and decreasing them for x>0.25. However, the overall agreement with measurements on wurtzite alloys remains poor. Chemical ordering along the [0001] direction in strained alloys is found to decrease their band gaps considerably, reducing the discrepancy with measurements. We discuss our results with regard to the current understanding of InGaN alloys.

• Sponsoring Organization: (US)
• OSTI ID: 40205260
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 2 Vol. 78; ISSN 0003-6951
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALLOYS
PHYSICS
STRAINS