ENERGY-BANDS IN QUANTUM-CONFINED SILICON LIGHT-EMITTING-DIODES

Measurements of the temperature dependence of the current-voltage char acteristics of heterojunction light-emitting diodes fabricated by depo siting indium tin oxide onto the surface of electrochemically etched p -type silicon (porous silicon) are presented, and the results are comp ared with those for adjacent devices formed on nonprocessed bulk silic on. The barrier height for the diodes which exhibit quantum confinemen t effects was determined to be 0.42 eV. Unlike the bulk silicon device s, the diodes prepared on porous silicon did not manifest a photovolta ic effect. These observations allow us to present a potential energy d iagram for porous silicon heterojunction diodes which indicates barrie rs in both the conduction band and the valence band.