Luminescence as a tool for crosslinking determination in plasma polysilylenes prepared from organosilanes

The photoluminescence (PL) in polysilanes during the change from linear one-dimensional (1D) Si chain to amorphous three-dimensional (3D) Si network was studied. The excitonic absorption observed in 1D Si at 320 nm undergoes a blue-shift and broadening of main-chain σ–σ* transitions on introducing branching and networking defects. With the gradual transition to the 3D structure the extensive redistribution of oscillator intensity along the absorption edge with the loss of the resolved σ–σ* band edge. Further, the gradual disappearance of main-chain exciton σ–σ* and appearance of the defect luminescence centred approximately at 450 nm and exhibiting red-shift with increasing 3D networking are observed.