Can pyrolysis of silane produce silicon nanocrystal?

Pyrolysis of silane can produce silicon nanocrystals or fines by direct nucleation of nanoparticles in thin films or nucleation and growth of nanoparticles with gases. These silicon nanocrystals and fines are important solar cell and/or electronic materials.

Why is Silane pyrolysis a porous agglomerate?

A high silane pyrolysis efficiency was obtained without the generation of excessive fines. Gas flow conditions near the base of the reactor were unfavorable for maintaining a bubbling bed with good heat transfer characteristics. Consequently, a porous agglomerate formed in the lower portion of the reactor.

What is Silane pyrolysis?

The earliest studies of silane pyrolysis assumed a straight forward decomposition of the silane molecule into silicon and hydrogen according to Eq. (1). However, later studies introduced an intermediate stage in accordance with Eq. (3).

How are silane fines formed?

The fines are essentially formed by wall deposition of the various polymeric Si species leaving the bed rather than by homogeneous decomposition of silane followed by nucleation. This is in disagreement with other studies where the homogeneous reaction of silane (mainly in the bubble phase) is considered to be responsible for the fine formation.

What are the major findings of silane conversion?

The major findings were as follows; silane conversion was essentially complete in the first few cm of the bed. The fines are essentially formed by wall deposition of the various polymeric Si species leaving the bed rather than by homogeneous decomposition of silane followed by nucleation.

Can a silane-Siemens reactor be used for polysilicon production?

According to Kang et al. (2012), the fines nucleation ratio in a silane-Siemens reactor is nearly identical with varying inlet silane mole fractions. Thus, for polysilicon production in a CVD reactor, controlling the silane inlet concentration is necessary to minimize silicon loss.