High efficiency GaN-based LEDs: light extraction by photonic crystals

The solar energy is able to supply humanity energy for almost another 1 billion years. Optical nano-antennas (ONAs) are an attractive technology for high efficiency, and low-cost solar cells. These devices can be classified to semiconductor nano-wires and metallic nano-antenna. Extensive studies have been carried out on ONAs to investigate their ability to harvest solar energy. Inspired by these studies, the scope of the chapter is to highlight the latest designs of the two main types of ONAs. The metallic nano-antennas are discussed based on the following points: plasmon, modeling, and performance of antenna designs using different configurations and materials. Moreover, the semiconductor nano-wires are studied thoroughly in terms of photonic crystals, antenna design with different patterns, nano-wire forms and materials. Also, the applications of ONAs and their fabrication aspects such as diode challenges are presented in detail. Finally, three novel designs of ONAs are presented and numerically simulated to maximize the harvesting efficiency.

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Enhancement of Deep-UV Light Extraction Efficiency from Bulk AlGaN with Photonic Crystals Fabricated by Nanoimprint Lithography

Chinese Journal of Luminescence ◽

10.3788/fgxb20143508.0998 ◽

2014 ◽

Vol 35 (8) ◽

pp. 998-1003

Author(s):

蔡钧安 CAI Jun-an ◽

秦志新 QIN Zhi-xin

Keyword(s):

Photonic Crystals ◽

Nanoimprint Lithography ◽

Extraction Efficiency ◽

Uv Light ◽

Light Extraction ◽

Light Extraction Efficiency ◽

Deep Uv

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Study on Modulation Bandwidth and Light Extraction Efficiency of Flip-Chip Light-Emitting Diode with Photonic Crystals

Micromachines ◽

10.3390/mi10110767 ◽

2019 ◽

Vol 10 (11) ◽

pp. 767 ◽

Cited By ~ 1

Author(s):

Hong Wang ◽

Ming Zhong ◽

Lijun Tan ◽

Wei Shi ◽

Quanbin Zhou

Keyword(s):

Photonic Crystal ◽

Photonic Crystals ◽

Flip Chip ◽

Extraction Efficiency ◽

Light Extraction ◽

Light Extraction Efficiency ◽

Experimental Result ◽

Modulation Bandwidth ◽

Light Emitting ◽

Current Densities

In this study, the photonic crystal structure is employed to increase both the light extraction efficiency and the modulation bandwidth of flip-chip GaN-based light-emitting diodes (LEDs). The finite difference time domain method is utilized to investigate the influence of structure of photonic crystals on the Purcell factor and light extraction efficiency of flip-chip GaN-based LEDs. Simulation results show that the modulation bandwidth is estimated to be 202 MHz at current densities of 1000 A/cm2. The experimental result of modulation bandwidth is in accord with the simulation. The optical f-3dB of the device achieves 212 MHz at current densities of 1000 A/cm2 and up to 285 MHz at current densities of 2000 A/cm2. This design of photonic crystal flip-chip LED has the potential for applications in high-frequency visible light communication.

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