Optimization of photonic crystal structure by FDTD method to improve the light extraction efficiency in silicon

Abstract

Silicon photonics technology is on its last hurdle to complete the system with active research on enhancing the light extraction efficiency of silicon. Silicon has a very poor radiative emission efficiency due to its indirect bandgap, thus making the probability of radiative recombination to be very low. The periodic quantum confinement structures such as photonic crystals (PhCs) can be tailored to increase the radiative recombination probability at the desired wavelengths. In this paper, we have optimized the silicon photonic crystal (Si PhCs) parameters to obtain luminescence at silicon bandgap and telecommunication wavelength using FDTD method. The extraction of photons is mostly conquered in the silicon structure that has lattice constant, a: 480 nm with radius, r: 140 nm and a: 500 nm with r: 160 nm. We have also observed the emissive photon luminescence that emerges in the most stable state of optical communication wavelength at 1310 nm.

Enhancing light extraction efficiency of GaN-based light-emitting diodes with reticulated photonic crystals

“…2(b), we can find that under the diffraction of reticulated PhCs, the TIR decreases to different degrees, and when the circular hole radius equals 70 nm, the TIR decreases to a minimum, then the LEE reaches the maximum enhancement. However, the LEE will eventually drop when the radius is too big thus reducing the confinement capability of the structure 21 …”

“…However, the LEE will eventually drop when the radius is too big thus reducing the confinement capability of the structure. 21 Figure 3 shows the electric field intensity profile in the steady state of planar LEDs and LEDs with circular hole radius equal to 20 and 70 nm. As calculated, the LEE of LEDs with 20-nm hole radius is 14.3%.…”

“…This method aims to overcome TIR and prevent lateral propagation of optical waveguides. Additionally, systematic research has been done to determine how LEE is affected by different structural characteristics, such as the filling factor, the depth of the PhCs, and the radius, to establish the optimal structure 12 . Recently, Ge et al.…”

“…Additionally, systematic research has been done to determine how LEE is affected by different structural characteristics, such as the filling factor, the depth of the PhCs, and the radius, to establish the optimal structure. 12 Recently, Ge et al designed a new complex periodic PhCs structure containing two kinds of hemispheres to get a high improvement of the LEE. 13 However, the structure was too complicated to fabricate.…”