Abstract
Enhanced electroluminescence (EL) of ITO/SiO <sub>x</sub> /Si-nanopyramid/p- Si/Al diode is investigated. By using low-power plasma enhanced chemical vapor deposition at high substrate temperature, anomalous (100)-oriented Si nanopyramids with a surface density of 1.6×10 <sup>10</sup> cm <sup>-2</sup> are synthesized at SiO <sub>x</sub> /Si interface prior to grow Si-rich SiO <sub>x</sub> film. Si nanopyramids greatly improve Fowler-Nordheim tunneling based carrier transport and benefit from less damaged oxide structure at lower biases. The turn-on voltage and threshold current density of the diode are reduced to 50 V and 0.2 mA/cm <sup>2</sup> , respectively. Defect-related blue-green EL are suppressed to enhance stable near-infrared EL at 30 nW with a lifetime >10 h. © 2006 American Institute of Physics.