Defect distribution in boron-reduced GaAs crystals grown by vapour-pressure-controlled Czochralski technique

Autor:	W. Ulrici, F.M. Kiessling, Peter Rudolph, Klaus Irmscher, Reinhard Krause-Rehberg, Martin Albrecht
Rok vydání:	2008
Předmět:	Materials science Silicon Doping Analytical chemistry Mineralogy chemistry.chemical_element Cathodoluminescence Condensed Matter Physics Crystallographic defect Inorganic Chemistry chemistry Vacancy defect Materials Chemistry Gallium Luminescence Boron
Zdroj:	Journal of Crystal Growth. 310:1418-1423
ISSN:	0022-0248
DOI:	10.1016/j.jcrysgro.2007.11.040
Popis:	GaAs crystals have been grown without B2O3 encapsulation by the vapour-pressure-controlled Czochralski (VCz) method to reduce undesired boron incorporation and to enable in situ control of the Ga/As ratio in the melt. Semi-insulating boron-reduced 2 and 3 in diameter twin-free GaAs crystals were grown from Ga-rich melts with compositions down to 46 at% arsenic. Cathodoluminescence (CL) measurements on crystals grown from Ga-rich melts show that the luminescence bands at 1.316 and at 1.441 eV are related to the BAs. Semiconducting GaAs crystals were grown from stoichiometric melts. The donor was incorporated by silicon doping or using fused silica crucibles. Performing positron annihilation lifetime spectroscopy shows that the low boron concentrations in our semi-conducting VCz GaAs result always in higher Ga vacancy concentrations compared to standard GaAs. CL bands due to optical transitions at 0.95 and 1.15 eV are related to auto-compensating (VGaSiGa)2− and (SiGaVGaSiGa)− complexes, respectively, and depend on the doping level.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::e7f32591b0603c9af66899964cba18c9 https://doi.org/10.1016/j.jcrysgro.2007.11.040 Zobrazit plný text záznamu Full Text from ScienceDirect