Characterization of porous silicon light emitting diodes in high current density conditions

P. Jaguiro /Bielorussian State University for Informatics and Electronics, Minsk, Bielorussia

M. Balucani, S. La Monica, S. Lazarouk, G. Maiello, A. Ferrari /Dipartimento di Ingegneria Elettronica, Universita 'La Sapienza' Roma, Italy

G.Masini /Dipartimento di Ingegneria Elettronica, Terza Universita di Roma,

Experimental current-voltage and current-brightness characteristic of Schottky diodes with the structure: metal (Al) - porous silicon - n-type silicon substrate are presented. The measurements are carried out with a pulsed current in the high current densities conditions, which usually lead to irreversible breakdown and junction damage if applied in continuous operation. Conditions and mechanism of Schottky diodes breakdown, based on avalanche multiplication of carriers, are analyzed and the limit of stimulating pulses duration, not yet resulting to irreversible breakdown, is countered. Design of the generator of powerful microsecond current pulses and registration scheme for brightness, current, voltage are considered. By use of this experimental tool the porous silicon light emitting diodes were investigated in the 2000...8000 A/sq.cm current density range.