Multicolor ${\rm ITO}/{\rm SiO}_{x}/{\rm p}\hbox{-}{\rm Si}/{\rm Al}$ Light Emitting Diodes With Improved Emission Efficiency by Small Si Quantum Dots

In this paper, multicolor ITO/SiO
x
/p-Si/Al light emitting diodes (LEDs) made by Si quantum dot (Si-QD) embedded Si-rich SiO
_x
grown by detuning the radio frequency (RF) plasma power under the plasma-enhanced chemical vapor deposition system are presented. With the Si-QD size shrinkage obtained by increasing the RF plasma powers from 30 to 70 W, the turn-on voltage of red, green, and blue ITO/SiO
_x
/p-Si/Al LEDs is found to increase from 70 to 99 V, with the maximum electroluminescent power increasing from 9 to 423 nW.