Leds Based on Oxidized Porous Polysilicon on a Transparent Substrate

Abstract

AbstractLight emitting devices (LEDs) based on porous polysilicon (PPS) have been fabricated on a transparent quartz substrate. Several structures have been developed, each consisting of a backside contact (ITO or p+ polysilicon), a light emitting PPS layer, a capping layer, and a metal top contact. Photoluminescence (PL) from PPS is similar to that of etched crystalline Si, peaking near 750 nn and showing degradation during 515 nm laser excitation with intensity <100 mW/cm2. This degradation disappears if PPS is oxidized after formation. Visible electroluminescence (EL) has been achieved in both oxidized and non-oxidized PPS devices with voltages under 10 V and current densities <200 mA/cm2.