Broadband and omnidirectional light harvesting enhancement of fluorescent SiC

Abstract

Abstract:In the present work, antireflective sub-wavelength structures have been fabricated on fluorescent 6H-SiC to enhance the white light extraction efficiency by using the reactive-ion etching method. Broadband and omnidirectional antireflection characteristics show that 6H-SiC with antireflective sub-wavelength structures suppress the average surface reflection significantly from 20.5 % to 1.01 % over a wide spectral range of 390-784 nm. The luminescence intensity of the fluorescent 6H-SiC could be enhanced in the whole emission angle range. It maintains an enhancement larger than 91 % up to the incident angle of 70 degrees, while the largest enhancement of 115.4 % could be obtained at 16 degrees. The antireflective sub-wavelength structures on fluorescent 6H-SiC could also preserve the luminescence spectral profile at a large emission angle by eliminating the Fabry-Pérot microcavity interference effect.

Omnidirectional luminescence enhancement of fluorescent SiC via pseudoperiodic antireflective subwavelength structures

“…However, it is usually limited by the availability of materials with appropriate refractive indices and thermal expansion coefficients. Antireflective subwavelength structures (ARS) have been proved as an ideal approach to enhance the light transmittance over a broad spectral bandwidth [14][15][16][17][18][19]. In addition, several recent works to increase the light extraction efficiency in GaN-based LEDs had been demonstrated by using photonic crystals with large index contrast [20], and self-assembled colloidal microlens arrays [3,21,22].…”

Fabrication of Broadband Antireflective Sub-Micro Structures on 4H-SiC by Mesh Patterning Etching

“…For that reason, dry etching with fluorine species, such as SF6, or CF4, is considered as the desirable method to form the textured surface of SiC. In order to fabricate the nanostructures on SiC substrate, a nano-scale patterning process such as e-beam lithography, nanoimprint lithography, or nanospheres lithography [13][14] is usually indispensable to create a mask layer for the subsequent etching process. However, e-beam lithography and nanoimprint lithography are not appropriate for mass production due to its high cost and time consumption.…”

Grating-based guided-mode resonance devices and degradation of their performance in real-life conditions

“…[1][2][3][4][5][6] The surfaces can also be microstructured to increase transmission of windows and for solar cell applications. [7][8][9][10][11][12][13][14][15] One-to-two layered grating-based filters and mirrors can replace thick multilayer analogues acting on basis of Bragg reflection. A stack of multiple layers can have significant fabrication imperfections so thin microengineered components are actively studied.…”