Hydrogen-induced defect engineering in dilute nitride semiconductors

In dilute nitrides, such as GaAsN, hydrogen-induced passivation of the electronic activity of N atoms offers an unprecedented opportunity to tune the electronic and structural properties of those materials. By deposition of hydrogen-opaque metallic masks on GaAsN and subsequent hydrogen irradiation, it is possible to alternate in the growth plane regions having the physical properties of GaAsN with those of N-passivated GaAsN. After reporting the main characteristics of deuterium diffusion in GaAsN as derived by secondary ion mass spectrometry, we present two examples of hydrogen-induced defect engineering. In the first case, we show that anisotropic strain fields can be created by selective H incorporation. The resulting in-plane symmetry breaking determines an in-plane polarization dependence of the light emitted along the crystal growth, otherwise unattainable in bulk GaAsN. Secondly, we report evidence of quantum confinement effects in dot-like structures obtained by in-plane patterning of the crystal band gap energy. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.