The electron effective mass, m(e)* and exciton radius, r(exc), have been derived in GaAs1-xNx (x less than or equal to 0.2%) by magneto-photoluminescence measurements. With increasing nitrogen concentration, m(e)* and r(exc) undergo a rapid increase and squeezing, respectively, already for x approximate to 0.1 %. Furthermore, in a hydrogen-irradiated GaAs1-xNx sample, the band gap widening induced by H maps on a profound modification of the conduction band. m(e)* (r(exc)) decreases (increases) with increasing H dose, until the GaAs value is obtained. First-principle calculations show that the formation of a specific N-H-2 dihydrogen complex leads to the removal of the electron localization caused by N incorporation in GaAs. (C) 2003 Elsevier B.V. All rights reserved.
Tuning of the electron effective mass and exciton wavefunction size in GaAs1-xNx
FIORENTINI, VINCENZO;
2004-01-01
Abstract
The electron effective mass, m(e)* and exciton radius, r(exc), have been derived in GaAs1-xNx (x less than or equal to 0.2%) by magneto-photoluminescence measurements. With increasing nitrogen concentration, m(e)* and r(exc) undergo a rapid increase and squeezing, respectively, already for x approximate to 0.1 %. Furthermore, in a hydrogen-irradiated GaAs1-xNx sample, the band gap widening induced by H maps on a profound modification of the conduction band. m(e)* (r(exc)) decreases (increases) with increasing H dose, until the GaAs value is obtained. First-principle calculations show that the formation of a specific N-H-2 dihydrogen complex leads to the removal of the electron localization caused by N incorporation in GaAs. (C) 2003 Elsevier B.V. All rights reserved.
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