Polysilanes backbone scission

It should be mentioned that these silicon-backbone polymers are highly absorptive, and must therefore be used in very thin films ( 30 nm), which can be prone to defects. Also, the principal electronic transition in these polysilane (with two-dimensional silicon backbone) and polysilane (three-dimensional silicon backbone) polymers when irradiated at 193 nm is most likely a (t-ct transition involving the all-silicon backbone. Due to this excitation, reaction pathways leading to scission of the Si-Si bonds lead to photodegradation of the polymer. 

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