Nitrogen-hydrogen complex in Ga Asx N1-x revealed by x-ray absorption spectroscopy
Nitrogen-hydrogen complex in Ga Asx N1-x revealed by x-ray absorption spectroscopy
复制标题
X 射线吸收光谱揭示 Ga Asx N1-x 中的氮氢络合物
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
M. Capizzi
中科院分区：
文献类型：
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作者：
G. Ciatto;F. Boscherini;A. A. Bonapasta;F. Filippone;A. Polimeni;M. Capizzi
GaAsN alloys belong to a class of semiconductors with fascinating physical properties. Indeed, a small amount of nitrogen incorporation in GaAs leads to a counterintuitive and large band-gap reduction, and to an unexpected sudden increase in the effective mass of electrons. Even more surprisingly, both electronic and structural changes can be reversed fully and in a tunable manner by hydrogen incorporation. In this paper, we combine x-ray absorption spectroscopy at the nitrogen edge with ab initio simulations to investigate the atomic geometry of $mathrm{N}ensuremath{-}mathrm{H}$ complexes in hydrogenated GaAsN. In this way, we provide experimental evidence that dihydrogen-nitrogen complexes with ${C}_{2mathrm{v}}$ symmetry are the most abundant species in hydrogenated GaAsN. This finding contradicts previous predictions of ``in-line' $mathrm{N}ensuremath{-}mathrm{H}_{2}{}^{*}$ complexes as the predominant species, and accounts for recent infrared absorption experiments.
GaAsN alloys belong to a class of semiconductors with fascinating physical properties. Indeed, a small amount of nitrogen incorporation in GaAs leads to a counterintuitive and large band-gap reduction, and to an unexpected sudden increase in the effective mass of electrons. Even more surprisingly, both electronic and structural changes can be reversed fully and in a tunable manner by hydrogen incorporation. In this paper, we combine x-ray absorption spectroscopy at the nitrogen edge with ab initio simulations to investigate the atomic geometry of $mathrm{N}ensuremath{-}mathrm{H}$ complexes in hydrogenated GaAsN. In this way, we provide experimental evidence that dihydrogen-nitrogen complexes with ${C}_{2mathrm{v}}$ symmetry are the most abundant species in hydrogenated GaAsN. This finding contradicts previous predictions of ``in-line' $mathrm{N}ensuremath{-}mathrm{H}_{2}{}^{*}$ complexes as the predominant species, and accounts for recent infrared absorption experiments.