Analysis of the recombination at the interface between
a metallic precipitate and a semiconductor matrix
A. Djemel1*, R.J. Tarento2
1 LPCS Université Mentouri Constantine 25000 Algérie
2 LPS Université Paris Sud Centre d’Orsay Bt 510 Cedex 91405 France
* Corresponding author: E-mail: firstname.lastname@example.org
Received: 07 July 2011; revised version accepted: 09 September 2011
A self consistent calculation of the barrier height and the effective recombination velocity at the interface between a metallic precipitate and a semiconductor matrix has been performed within the Schottky-Mott theory of metal-semiconductor contacts. The quasi-Fermi level for the majority carrier is considered flat in the space-charge region. However, the quasi-Fermi level on the minority carrier is not constant in the space-charge region, nor in the neutral region. The carrier recombination is determined by thermo ionic emission law. We investigated the recombination dependence on the semiconductor doping concentration and the precipitate size. The precipitate size has a dramatic effect on the barrier height and the effective recombination velocity. The surface charge density on the metallic precipitate decreases as Sigma=Aexp(-alpha*R) when the size increases, depending on the doping concentration. The barrier height reaches a limiting value controlled by the doping concentration and the precipitate size.
Keywords: Recombination; Precipitate; Interface.