Nearest-neighbor distributions in Ga{sub 1-x}In{sub x}N{sub y}As{sub 1-y} and Ga{sub 1-x}In{sub x}N{sub y}As{sub 1-y-z}Sb{sub z} thin films upon annealing

Journal Article · Tue Mar 15 00:00:00 EST 2005 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.71.125309· OSTI ID:20666269

Lordi, Vincenzo; Yuen, Homan B; Bank, Seth R; Wistey, Mark A; Harris, James S; Friedrich, Stephan ^[1]

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1. Solid State and Photonics Laboratory, Stanford University, Stanford, California 94305 (United States)

We examine the distribution of N-In nearest-neighbor bonds in GaInNAs(Sb) quantum wells (QWs) and observe quantitatively the evolution of the distribution during thermal annealing. We use near-edge x-ray absorption fine structure to compare the behavior of compressively strained quantum wells with relaxed thick-film samples, and find no significant effect of strain on the nearest-neighbor bonding. Photoluminescence (PL) and electroreflectance (ER) spectroscopies are used to quantitatively measure the distribution of N-In nearest-neighbor states for a series of variously annealed GaInNAsSb QW samples. We find that increased annealing temperature or time leads to a blueshift of the band gap that saturates after sufficient annealing. This saturation is related to a thermodynamic equilibration of the N-In nearest-neighbor bonding in the material toward highly In-coordinated states, from an as-grown material having a nearly random bonding arrangement dominated by N-Ga bonds. The different N-In nearest-neighbor states form a fine splitting of the band gap of the material. The average spacing between these levels is found to be considerably smaller for GaInNAsSb ({approx}18 meV) than for GaInNAs ({approx}35 meV). Furthermore, we present absorption measurements that reveal an increased optical efficiency of the higher In-coordinated N states that form upon annealing. Additionally, the line shape observed at room temperature in all of the spectroscopic measurements is Gaussian, indicating a strong exciton-phonon coupling in these alloys.

• OSTI ID: 20666269
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 71, Issue 12; Other Information: DOI: 10.1103/PhysRevB.71.125309; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
ABSORPTION SPECTROSCOPY
ANNEALING
ANTIMONY COMPOUNDS
ARSENIC COMPOUNDS
CHEMICAL BONDS
COUPLING
ENERGY GAP
EXCITONS
FINE STRUCTURE
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
MEV RANGE 10-100
PHONONS
PHOTOLUMINESCENCE
QUANTUM WELLS
SEMICONDUCTOR MATERIALS
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
X RADIATION
X-RAY SPECTROSCOPY