Silicon defect and nanocrystal related white and red electroluminescence of Si-rich SiO2 based metal-oxide-semiconductor diode

Abstract

Silicon defect and nanocrystal related white and red electroluminescences (EL) of Si-rich SiO2 based on metal-oxide-semiconductor (MOS) diode using transparent electrode contact are reported. The 500nm-thick Si-rich SiO2 film on n-type Si substrate is synthesized using multi-recipe Si-ion-implantation or plasma enhanced chemical vapor deposition (PECVD). After 1100 degrees C annealing for 3 hrs, the PL of Si-ion-implanted sample at 415 rim and 455 rim contributed by the weak-oxygen bond and neutral oxygen vacancy defects is observed. The white-light EL spectrum was observed at reverse bias, which originates from the tunneling and recombination intermediate state of SiO2:Si+ at a threshold current and voltage of 1.56 mA and 9.6 V, respectively. The maximum EL power of 110 nW is obtained at biased voltage of 25 V. The linear relationship between the optical power and injection current with a corresponding slope of 2.16 mu W/A is obtained. The 4-mn nanocrystallite silicon (nc-Si) is precipitated in the 240nm-thick PECVD grown silicon-rich SiO2 film annealed at 1100 degrees C for 30 min with Indium-tin-oxide (ITO) of 0.8 min in diameter, which contributes PL at 760 rim. The peak wavelength of the EL spectra coincides well with the PL. The threshold cur-rent and voltage are 86 V and 1.08 mu A, respectively. The power-current (P-I) slope is determined as 697 mu W/A. The carrier injection mechanism is dominated by Fowler-Nordheim(F-N) tunneling.