Nano-silicon is a nanostructured material in which quantum or spatial confinement is the origin of the material's luminescence. When nano-silicon is broken into colloidal crystalline nanoparticles, its luminescence can be tuned across the visible spectrum only when the sizes of the nanoparticles, which are obtained via painstaking filtration methods that are difficult to scale up because of low yield, vary. Bright and tunable colloidal amorphous porous silicon nanostructures have not yet been reported. In this letter, we report on a 100 nm modulation in the emission of freestanding colloidal amorphous porous silicon nanostructures via band-gap engineering. The mechanism responsible for this tunable modulation, which is independent of the size of the individual particles and their distribution, is the distortion of the molecular orbitals by a strained silicon-silicon bond angle. This mechanism is also responsible for the amorphous-to-crystalline transformation of silicon. This journal is
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We would like to thank Qingxiao (Vincent) Wang for his help on the STEM and EELS and Dr Dalaver Anjum for acquiring the HRTEM images. We also thank King Abdullah University of Science and Technology (KAUST) for financial support.
ASJC Scopus subject areas
- General Physics and Astronomy
- Physical and Theoretical Chemistry