Super-hierarchiral quantum effects and semiconducting polymers with 14-group elements (2): Visble and near infrared photoluminescent materials by quantum confinement of pyrolitic alkylpolysilynes

Si crystal is a typical non-luminous semiconductor due to indirect band gap of 1.1eV. Herein we report that pyrolitic product of n-butyl polysilyne turns to highly luminous amorphous silicon-like materials (Raman Si-Si band 460cm-1), emitting 460-750nm (1.6-2.7eV). The emitting wavelengths were controlled by the choice of pyrolytic temperature and time of the polysilyne sealed in vacuo. Of particular interest is that i-butyl polysilyne afforded crystalline Si (Raman Si-Si band 510cm-1 typical for crystal Si), when i-butyl polysilyne was treated at 500C in vacuo. These findings are very promising in developing novel highly lumiuous Si-related materials and Si thin film without the use of dangerous SiH₄ gas.