Nearest-neighbor configuration in (GaIn)(NAs) probed by x-ray absorption spectroscopy.
Ga(1-x)In(x)N(y)As(1-y) is a promising material system for the fabrication of inexpensive "last-mile" optoelectronic components. However, details of its atomic arrangement and the relationship to observed optical properties is not fully known. Particularly, a blueshift of emission wavelength is observed after annealing. In this work, we use x-ray absorption fine structure to study the chemical environment around N atoms in the material before and after annealing. We find that as-grown molecular beam epitaxy material consists of a nearly random distribution of atoms, while postannealed material shows segregation of In toward N. Ab initio simulations show that this short-range ordering creates a more thermodynamically stable alloy and is responsible for blueshifting the emission.
Lordi
Vincenzo
V
Solid State and Photonics Laboratory, Stanford University, Stanford, California 94305, USA. vlordi@snow.stanford.edu
Gambin
Vincent
V
Friedrich
Stephan
S
Funk
Tobias
T
Takizawa
Toshiyuki
T
Uno
Kazuyuki
K
Harris
James S
JS