J. Phys. III France
Volume 7, Numéro 11, November 1997
Page(s) 2145 - 2151
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. Neffati1

1  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)

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.

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