Hello dear people,

I would like to ask a question about volumetric and surface reactions. Let me use an example. I have the reactions:

SiH4 -> SiH2 + H2 , (volumetric reaction) [1] SiH2 -> Si + H2 , (surface reaction) [2]

The SiH2 produced by [1] is diffused and adsorbed in the surface. In the surface is decomposed and produces Si like in [2].

I read the manual. Should I use just surface chemistry and make SiH2 as site species? Or I must set two materials like SiH2 (in volume) and another one SiH2_s (site species) and impose both reactions? Does anybodu has an idea?

Thanks in advance.

[bobo]

hi,

the post is quite old, but i'm having the same problem. site species are poorly explained in the manual.

so if anyone has information about the problem above, i'd appreciate this

[Jiuan]

If these two reaction are expressed like this
SiH4 (g)-> SiH2 (g) + H2 (g) , (volumetric reaction) [1]
SiH2 (g)-> Si (s)+ H2 (g) , (surface reaction) [2]

then we don't have to create a site speicies for SiH2. We can just defind one volumetric reation and one surface reaction in Fluent.

If the above reactions are written as
SiH4 (g)-> SiH2 (g) + H2 (g) , (volumetric reaction) [1]
SiH2 (g)-> SiH2 (s) (surface reaction) [2]
SiH2 (s)-> Si (s)+ H2 (g) , (surface reaction) [3]

Then we have to define site species for SiH2 (s).

Originally Posted by bobo

hi,

the post is quite old, but i'm having the same problem. site species are poorly explained in the manual.

so if anyone has information about the problem above, i'd appreciate this