Luminescence from hydrogen‐free silicon nanostructures in amorphous hydrogenated silicon

Luminescence decay in hydrogenated amorphous silicon and silicon nanostructures

“…It is known in the porous Si (p-Si) that the Si nanoparticles with the diameter from 3 to 5 nm have the bandgaps from 1.8 to 1.5 eV [9], which correspond to the Urbach tail region in a-Si:H. Therefore, it is possible that the Urbach tail in a-Si:H is due to the optical absorption of the hydrogen-free Si nanostructures and the luminescence is due to the radiative recombination of excitonic electron-hole pairs in the hydrogen-free Si nanostructures. The authors propose the hydrogen-free Si nanostructure model of the luminescence center in a-Si:H from the similarity of the excitation energy dependence of the luminescence peak energy between a-Si:H and the Si nanoparticles in p-Si [10]. Here, we show that the luminescence decay in a-Si:H supports the hydrogen-free Si nanostructure model of the luminescence center by comparing with that in p-Si.…”

“…The luminescence in a-Si:H is shown to be due to the recombination of excitonic electron-hole pairs quantum-confined in the hydrogen-free Si nanostructures from the excitation energy dependence of the luminescence spectrum [10]. The luminescence consists of the fast and slow luminescence.…”

Luminescence gap in hydrogenated amorphous silicon

“…5 in order to confirm if the slope of the dependency is 0.65, because it is reported in Ref. [12] that the slope agrees with 0.65 of the slope in the porous Si [13] so that the luminescence center may be the hydrogen-free Si nanostructures in a-Si:H.…”

Origin of strong white electroluminescence from dense Si nanodots embedded in silicon nitride

“…However, silicon nitride generally contains various defect centers such as Si and N dangling bonds, which can act as radiative EL centers to give rise to light emission in the yellow to violet region [15,16]. This complicates the EL properties of the silicon nanostructure/silicon nitride systems and more importantly, the luminescence properties of the Si nanostructures can degrade since these defects have radiative lifetimes on the order of nanoseconds and they are much shorter than those of Si nanostructures [2,17]. Although recent studies have explored efficient EL from the silicon nitride system, the progress so far is slow [12][13][14][15][16]18].…”