VISIBLE-LIGHT FROM ALUMINUM-POROUS SILICON SCHOTTKY JUNCTIONS

The fabrication technologies and the properties of light-emitting devi ces based on Al-porous silicon (PS) Schottky junctions have been devel oped. Bright light emission, visible by the naked eye at normal daylig ht, is observed at the edge of the electrodes under reverse bias, The electroluminescence (EL) starting voltage is in the range 5-18 V, depe nding on the doping level of Si substrate. The current level at which the EL starts is around 1 mA for devices of 2.3 x 10(-3) cm(2) area. T he light emission intensity increases with increasing current density. EL spectra were broad, covering the whole visible range. The time sta bility was excellent for all rested devices: the EL intensity did not show remarkable changes, even after more than ten days of continuous l ight emission at voltages fewer than thermal breakdown.