Effect of photonic crystals on the light extraction of GaN-based LED for different polarization modes of spontaneous radiation

Feng, Liangsen; Zhang, Ning; Wang, Junxi; Li, Jinmin

doi:10.1016/j.rinp.2019.102632

Cited by 14 publications

(10 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A transverse electric (TE) polarized dipole source was located in the center of the InGaN MQW with a wavelength range of 450 ~ 650 nm. TE polarization is known to dominate in the entire visible wavelength range [38,39]. The transmittance of propagating light is calculated by a transmittance monitor placed below the Al reflector.…”

Section: ⅱ Results and Discussionmentioning

confidence: 99%

Sub-Micron Monolithic Full-Color Nanorod LEDs on A Single Substrate

Kim

et al. 2023

IEEE Photonics J.

View full text Add to dashboard Cite

The extended reality (XR) display, including augmented reality (AR) and virtual reality (VR), requires ultrahigh-resolution and high-luminance pixel technology. GaNbased micro-LEDs are the most promising for high-density pixel applications. However, it is necessary to simultaneously fabricate full-color R/G/B emitters on a single substrate. Moreover, the efficiency droop at long wavelengths with high-indium InGaN still remains a challenge. The InGaN nanorod has the potential to realize monolithic R/G/B LEDs on a single substrate, and the Al reflector has a light reflectance that can dramatically improve light extraction efficiency. Here, we designed sub-micron monolithic full-color R/G/B nanorod LEDs with an Al core-shell reflector on single chip. The optimal structures for light confinement and vertical light extraction by single InGaN nanorod R/G/B LED structures were identified. The single nanorod with Al core-shell structure dramatically increased the light extraction efficiency, and showed an improvement of more than 20%, especially in the red wavelength. As a result, by introducing a longlength nanorod structure, we have successfully designed a new submicron pixel with full-color R/G/B LEDs operating within 1 x 1 μm2 size. This unique design will be a key factor in enabling the next generation of AR and VR displays that require ultra-small and compact pixels.

show abstract

Section: ⅱ Results and Discussionmentioning

confidence: 99%

Sub-Micron Monolithic Full-Color Nanorod LEDs on A Single Substrate

Kim

et al. 2023

IEEE Photonics J.

View full text Add to dashboard Cite

show abstract

“…24 Many of the above-mentioned research methods focus on the improvement of internal quantum efficiency, which value has almost reached the limit of the material, 25 while the improvement of external quantum efficiency still has room for development. 26 Compared with other methods aimed at improving the external quantum efficiency, the design of PhC structure has a high degree of freedom. Moreover, Bragg scattering can be caused by the surface grating effect, and the propagation direction of light can be controlled by the band gap effect to improve the external quantum efficiency, thus the light extraction efficiency (LEE) is expected to be improved.…”

Section: Introductionmentioning

confidence: 99%

Enhancing light extraction efficiency of GaN LED by combining complex‐period photonic crystals with doping

Chen

Wang

2023

J Am Ceram Soc.

View full text Add to dashboard Cite

The light extraction efficiency (LEE) of GaN‐based light‐emitting diodes (LEDs) was limited by intense total internal reflection and the photothermal effect. In order to solve this problem, a method to synergistically control the LEE of GaN‐based LEDs by combining the complex‐period photonic crystals (PhCs) with M (M = Al, In) material doping is proposed. The forbidden band width of two‐dimensional (2D) PhC array, three‐dimensional (3D) LED model, M doping, and electromagnetic field distribution are investigated respectively. By doping the M, the LED emission wavelength range is regulated to achieve the dual‐band emission. Furthermore, a triangular complex‐period photonic structure is introduced to establish stacked or etched PhCs models. By combining the plane wave expansion and finite difference time domain algorithm, the structural parameters of PhCs and M concentration dependent LEE are investigated, and the electromagnetic field distribution is explored also. The results show that the optimal LEEs can be achieved are 19.08% and 13.96% for blue light and ultraviolet, respectively, which are larger than that of traditional flat‐panel LED (4%). This work provides theoretical results and technical support for the design of LEDs with high luminous efficiency.

show abstract

“…Yin et al [ 40 ] exhibited an improved optical bandwidth and frequency performance of GaN-based LEDs by using nanoholes PC structure with a well-defined period and radius to achieve high-speed operation for visible light communication. Feng et al [ 41 ] presented the enhanced TE- and TM-mode LEE of GaN-based LEDs with cylindrical p-GaN, MQWs, and n-GaN PC structure through the FDTD method. The calculated results also indicate that the TM-mode LEE is higher than TE-mode LEE for GaN-based LEDs with PC structure owing to the light waveguide.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Photonic-Crystal-Structured p-GaN Nanorods Fabricated by Polystyrene Nanosphere Lithography Method to Improve the Light Extraction Efficiency of InGaN/GaN Green Light-Emitting Diodes

2021

View full text Add to dashboard Cite

We fabricated the photonic-crystal-structured p-GaN (PC-structured p-GaN) nanorods using the modified polystyrene nanosphere (PS NS) lithography method for InGaN/GaN green light-emitting diodes (LEDs) to enhance the light extraction efficiency (LEE). A modified PS NS lithography method including two-times spin-coating processes and the post-spin-coating heating treatment was used to obtain a self-assembly close-packed PS NS array of monolayer as a mask and then a partially dry etching process was applied to PS NS, SiO2, and p-GaN to form PC-structured p-GaN nanorods on the InGaN/GaN green LEDs. The light output intensity and LEE of InGaN/GaN green LEDs with the PC-structured p-GaN nanorods depend on the period, diameter, and height of PC-structured p-GaN nanorods. RSoft FullWAVE software based on the three-dimension finite-difference time-domain (FDTD) algorithm was used to calculate the LEE of InGaN/GaN green LEDs with PC-structured p-GaN nanorods of the varied period, diameter, and height. The optimal period, diameter, and height of PC-structured p-GaN nanorods are 150, 350, and 110 nm. The InGaN/GaN green LEDs with optimal PC-structured p-GaN nanorods exhibit an enhancement of 41% of emission intensity under the driving current of 20 mA as compared to conventional LED.

show abstract

Effect of photonic crystals on the light extraction of GaN-based LED for different polarization modes of spontaneous radiation

Cited by 14 publications

References 24 publications

Sub-Micron Monolithic Full-Color Nanorod LEDs on A Single Substrate

Sub-Micron Monolithic Full-Color Nanorod LEDs on A Single Substrate

Enhancing light extraction efficiency of GaN LED by combining complex‐period photonic crystals with doping

Investigation of Photonic-Crystal-Structured p-GaN Nanorods Fabricated by Polystyrene Nanosphere Lithography Method to Improve the Light Extraction Efficiency of InGaN/GaN Green Light-Emitting Diodes

Contact Info

Product

Resources

About