Spatial-distribution of recombination centers in gaaste - effects of the doping level

The distribution in liquid-encapsulated-Czochralski (LEC) GaAs:Te wafers of point and complex defects has been investigated together with their influence on the minority-carrier diffusion length L. Three wafers with different Te-doping concentration (2.2 X 10(17), 4.5 X 10(17), and 1.5 X 10(18) cm-3...

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Bibliographic Details
Authors: Castaldini, A., Calvallini, A,., Fraboni, B, Méndez Martín, María Bianchi, Piqueras De Noriega, Francisco Javier
Format: article
Publication Date:1994
Country:España
Institution:Universidad Complutense de Madrid (UCM)
Repository:Docta Complutense
Language:English
OAI Identifier:oai:docta.ucm.es:20.500.14352/58965
Online Access:https://hdl.handle.net/20.500.14352/58965
Access Level:Open access
Keyword:538.9
Te Wafers
Cathodoluminescence
Defects
Física de materiales
Description
Summary:The distribution in liquid-encapsulated-Czochralski (LEC) GaAs:Te wafers of point and complex defects has been investigated together with their influence on the minority-carrier diffusion length L. Three wafers with different Te-doping concentration (2.2 X 10(17), 4.5 X 10(17), and 1.5 X 10(18) cm-3) have been studied by means of the electron-beam-induced-current (EBIC) mode of scanning electron microscopy and of the surface photovoltage (SPV) method. The morphology and electrical activity of the defects observed across each wafer have been correlated to the formation and distribution of deep electronic levels, which are significantly affected by the tellurium concentration. The diffusion length has been found to be mainly controlled by deep levels associated with dislocations. EBIC localized measurements of L and of the net ionized free-carrier concentration provide evidence for the influence of Te concentration on impurity segregation at complex defects.