DOI: 10.1051/jp3:1997246
J. Phys. III France 7 (1997) 2145-2151

The Metastability of Deep Donor Defects in Semiconductor Compounds

J.C. Bourgoin¹, M. Zazoui², S. Alaya³ and T. Neffati<sup>1

1</sup>  Groupe de Physique des Solides, Universités Paris 6 et Paris 7, Tour 23, 2 place Jussieu, 75251 Paris Cedex 05, France
²  Laboratoire d'Opto-Électronique, Université Hassan II, Faculté des Sciences et Techniques de Mohammedia, Boulevard Hassan II, B.P. 146, Mohammedia, Maxoc
³  Laboratoire des Semiconducteurs, Faculté des Sciences de Monastir, Route de Kairouan, 5000 Monastir, Tunisie

(Received 4 February 1997, accepted 11 August 1997)

Abstract
There is a whole class of deep donor defects which exhibit a metastable character, i.e. transform into a metastable state after a specific photo-excitation. Typical examples are the EL2 defect in GaAs and the DX center in several ternary III-V compounds. We shall present other defects which behave similarly, demonstrating that this metastable character is not specific of a defect but is a common behaviour of a class of defects. We shall also demonstrate that for all these defects the thermal excitation of electrons takes place in the L conduction band and that the metastable chaxacter is a direct consequence of this. This leads to a new concept of a metastable state, a result of an electronic metastability due to a band structure effect and not to a strong electron-phonon interaction.

© Les Editions de Physique 1997