Effects of process conditions on the properties of silicon nanoparticles synthesized by gas phase reactions using...

Silicon nanoparticles were synthesized by passing monosilane through a quartz tube wrapped with Inductive Coupled Plasma (ICP) coil. Microstructures of synthesized silicon nanoparticles were investigated with various process conditions. To research the effects of process parameters on the properties of nanoparticles, we verified the partial pressure of monosilane, the plasma power and the working pressure. The highly crystalline silicon nanoparticles were only achieved at the proper partial pressure of the reactive gas and plasma power. Partial pressure determined not only the particle size but also the crystallinity of the nanoparticles. The plasma power was controlled from 50 to 100 W which determined not the particle size but the crystallinity of nanoparticles. Especially, too low a power resulted in amorphous particles with an average sizes of 5.25 nm. As the working pressure increased, the amount of produced nanoparticles linearly increased and the maximum production yield was at 76 mg/hr. Controlling those parameters, we achieved monodispersed single crystalline silicon nanoparticles with an average diameter of 7.52 nm. Silicon nanoparticles in this study can be applied to light absorbing material for solar cells and the wavelength down-converter material of Light Emitting Diode (LED).