Title: White light emission from silicon nanoparticles,
Abstract: As one of the most important semiconductors, silicon (Si) has been used to
fabricate electronic devices, waveguides, detectors, and solar cells etc.
However, its indirect bandgap hinders the use of Si for making good emitters1.
For integrated photonic circuits, Si-based emitters with sizes in the range of
100-300 nm are highly desirable. Here, we show that efficient white light
emission can be realized in spherical and cylindrical Si nanoparticles with
feature sizes of ~200 nm. The up-converted luminescence appears at the magnetic
and electric multipole resonances when the nanoparticles are resonantly excited
at their magnetic and electric dipole resonances by using femtosecond (fs)
laser pulses with ultralow low energy of ~40 pJ. The lifetime of the white
light is as short as ~52 ps, almost three orders of magnitude smaller than the
state-of-the-art results reported so far for Si (~10 ns). Our finding paves the
way for realizing efficient Si-based emitters compatible with current
semiconductor fabrication technology, which can be integrated to photonic
circuits.