Visible light from aluminum-porous silicon Schottky junctions

S. Lazarouk*, P. Jaguiro*, S. Katsouba*, A. Ferrari+^, S. La Monica+, G. Maiello+, and G. Masini+

^* Bielorussian State University of Informatics and Electronics, P Brovki 6 220600 Minsk Byelorussia
⁺ Universita di Roma 'La Sapienza', Facolta di Ingegneria, Dipartimento di Ingegneria Elettronica, Via Eudossiana 18 00184 Rome Italy

Abstract

The fabrication technologies and the properties of light-emitting devices based on Al-porous silicon (PS) Schottky junctions have been developed. Bright light emission, visible by the naked eye at normal daylight, is observed at the edge of the electrodes under reverse bias.

The electroluminescence (EL) starting voltage is in the range 5-18 V, depending on the doping level of Si substrate. The current level at which the EL starts is around 1 mA for devices of 0.23 sq.mm area. The light emission intensity increases with increasing current density, EL spectra were broad, covering the whole visible range.

The time stability was excellent for all tested devices: the EL intensity did not show remarkable changes, even after more than ten days of continuous light emission at voltages lower than thermal breakdown.

Author Keywords: Aluminium; Silicon; Schottky barrier; Electrochemistry