Effect of photonic crystal stop-band on photoluminescence ofa−Si1−xCx:H

Abstract

Effects associated with the change in the local density of photonic states in a periodic structure based on alternating a-Si1−xCx:H and a-SiO2 amorphous layers forming a one-dimensional (1D) photonic crystal have been analyzed. The use of a-Si1−xCx:H as the emitting material made it possible to examine the transformation of the photoluminescence spectrum contour that is comparable in width with the photonic stop-band. It was experimentally demonstrated that the emission is enhanced and suppressed in the vicinity of the stop-band. The relative intensities of the luminescence peaks at different edges of the stop-band vary with the detuning of the stop-band position and photoluminescence peak of a single a-Si1−xCx:H film. The Purcell effect in the system under consideration was theoretically described by the method in which the local density of photonic states is calculated in terms of a 1D model. It was shown that the specific part of local density of states substantially increases at the long-wavelength (low-frequency) edge of the stop-band of a 1D photonic crystal as a result of the predominant localization of the electric field of the light wave in the spatial regions of a-Si1−xCx:H which have a higher relative permittivity as compared with a-SiO2.

Application of the generalized Kirchhoff's law to calculation of photoluminescence spectra of one-dimensional photonic crystals

“…Here it should be noted that 1D models can satisfactorily describe the experimental SE spectra of quasione-dimensional structures composed of isotropic layers [15,21,[31][32][33][34][35]. As an example, there is an approach using the concept of the electromagnetic density of modes in 1D periodic structures [36][37][38][39], that can be exploited in calculations of SE spectra; it is discussed in comparison with the indirect method from Kirchhoff's law in [40].…”

Polymeric Planar Microcavities Doped with a Europium Complex

“…The layer thicknesses were employed as fitting parameter for the reflectance data, while the optical functions of PVK, PAA and PS were previously measured and reported in other publications [43,48]. The retrieved geometrical thicknesses and the refractive index just mentioned were then employed to model the angular dispersion of the microcavity transmittance spectrum and the local density of photonic states (LPDOS) as described in [49].…”

Сферический распределенный брэгговский отражатель на основе a-Si-=SUB=-1-x-=/SUB=-C-=SUB=-x-=/SUB=- : H и a-SiO-=SUB=-2-=/SUB=-

“…Чередование слоев обеспечивалось переключением газовых потоков [11,12]. плоскими электродами равнялось 50 mm.…”

“…Во всех исследованных спектрах наблюдалась широкая полоса отражения, которая, как и в планарных распределенных брэгговских отражателях [11,12,[14][15][16][17][18], возникает за счет брэгговского отражения от группы слоев с периодически меняющимся показателем преломле-ния. Спектральное положение центра полосы брэгговского отражения незначительно смещается при регистрации отражения в разных точках поверхности СРБО.…”