Synthesis of Si nanopyramids at SiO_x/Si interface for enhancing electroluminescence of Si-rich SiO_x

摘要

Enhanced electroluminescence (EL) of ITO/SiO_x/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 X 10~(10) cm~(-2) are synthesized at SiO_x/Si interface prior to grow Si-rich SiO_x 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~2, respectively. Defect-related blue-green EL are suppressed to enhance stable near-infrared EL at 30 nW with a lifetime > 10 h.