Stable electroluminescence of nanocrystalline silicon device activated by high pressure water vapor annealing

Electroluminescence (EL) and electrical properties of nanocrystalline porous silicon (PS) diodes have been sufficiently improved by introducing high pressure water vapor annealing into the active PS layer. The EL emission is significantly enhanced without affecting the operating voltage. In addition, the fabricated device shows no degradations in both the EL intensity and the diode current density under a dc operation. The EL spectra coincide well with the photoluminescence ones. The obtained high EL performance is presumably caused by complete passivation of nanocrystalline silicon surfaces by thin tunnel oxides with mostly unstrained uniform network and little interfacial trapping defects.