Optimizing the parameter space for increased crystallinity of silicon nanoparticles grown in the gas phase

Various plasma process parameters such as coupled power, process pressure (p), gas flow, and source gas ratios (SiH₄:H₂) play crucial roles in determining the size and crystallinity of the synthesized Si nanoparticles (NPs). One of the less studied parameters for NP growth is the inter-electrode distance, d. Our study focuses on the effect of d and demonstrates how a reactor with larger d (refers to d=30mm) is a simple method to enhance the crystalline ratio of NPs produced in them compared with a standard d (refers to d=10mm). Increasing d or p is not strictly equivalent, and we show that for our reactor p>0.8mbar is most effective at d=30mm to obtain purely crystalline NPs. We also establish how the larger d opens up a wider parameter space for the synthesis of crystalline Si NPs. Completely crystalline silicon NPs synthesized in this study at p=0.8mbar and larger d of 30mm.