Holographic Fabrication and Optical Property of Graded Photonic Super-Crystals with a Rectangular Unit Super-Cell

Abstract

Recently developed graded photonic super-crystals show an enhanced light absorption and light extraction efficiency if they are integrated with a solar cell and an organic light emitting device, respectively. In this paper, we present the holographic fabrication of a graded photonic super-crystal with a rectangular unit super-cell. The spatial light modulator-based pixel-by-pixel phase engineering of the incident laser beam provides a high resolution phase pattern for interference lithography. This also provides a flexible design for the graded photonic super-crystals with a different ratio of length over the width of the rectangular unit super-cell. The light extraction efficiency is simulated for the organic light emitting device, where the cathode is patterned with the graded photonic super-crystal. The high extraction efficiency is maintained for different exposure thresholds during the interference lithography. The desired polarization effects are observed for certain exposure thresholds. The extraction efficiency reaches as high as 75% in the glass substrate.

Generation of over 1000 Diffraction Spots from 2D Graded Photonic Super-Crystals

“…Multiple-beam laser interference lithography has been used for the holographic fabrication of GPSCs [12][13][14]. Here the interference pattern is used to design the pattern for the electron-beam lithography and also as an input for the FDTD simulation of E-field intensity and reflection from the GPSC.…”

“…Very recently, graded photonic super-crystals (GPSCs) have been fabricated through the interference lithography by two sets of multiple beams arranged in a cone geometry [12][13][14]. The GPSC has two sets of lattices: the rod size (or hole size) increases gradually along one direction in one set of lattices while the other set decreases their sizes gradually.…”

“…The GPSC has two sets of lattices: the rod size (or hole size) increases gradually along one direction in one set of lattices while the other set decreases their sizes gradually. GPSC has dual period and even dual symmetry: The square lattices in GPSC have a small period while graded regions have their own symmetry and period [12][13][14]. GPSCs can be used to enhance the broadband light trapping in an Si solar cell, broadband light extraction from organic light emitting diode, and to form a resonance cavity at the boundary of graded and less-graded regions [15][16][17].…”

Photonics in nature and bioinspired designs: sustainable approaches for a colourful world

“…55,56 Nowadays, a spatial light modulator is generally used for creating defects or for engineering more exible designs. [57][58][59] Nanoimprint lithography (NIL) is a technique where the nanopattern present on a stamp originally made by EBL is transferred by employing pressure and temperature (Thermal NIL, also known as hot embossing), or pressure and UV light (UV NIL) against a polymer (Fig. 8C), which may then be used as an optical waveguide itself or as a resist for pattern transfer to another substrate.…”

Effects of Photonic Band Structure and Unit Super-Cell Size in Graded Photonic Super-Crystal on Broadband Light Absorption in Silicon

“…super-cell) with graded size of rods in air is possible through parallel computations in cloud-based virtual computers [12][13][14][15][16]. We titled such a PhC as a graded photonic super-crystal (GPSC) [12][13][14][15][16][17]. The graded square-symmetric lattices form a cluster that can be arranged in 4-, 5-, or 6-fold symmetries [12,13].…”