Sheffield University Research Team Displays LED Grown on Semi-polar GaN or Sapphire

News Source: 

A research team from Sheffield University has recently published there latest findings of growing LEDs on semi-polar GaN or sapphire on Applied Physics Letter recently.

(a) SEM image of a micro-rod GaN template; (b) TEM image of the (11-22) GaN overgrown on micro-rods; (c) XRD FWHMs of the overgrown (11-22) GaN and (11-22) GaN template, measured at azimuth angles ranging from 0° to 180°; (d) schematic of (11-22) InGaN SQW LED. (Photo courtesy of Applied Physics Letter)

The team from Sheffield University’s  Department of Electronic and Electrical Engineering were able to demonstrate semipolar InGaN single-quantum-well LEDs that emitted green, yellow-green, yellow and amber colors. The LEDs were grown on an overgrown semipolar (11-22) GaN on micro-rod array templates, which were fabricated on GaN grown on m-plane sapphire.

Compared to commercial LEDs grown on the c-Plane, the research team’s green LEDs grown on the semipolar material showed significantly reduced blue-shift in the emission wavelength with increasing driving current. The same observations were made in blue-shifts for the yellow-green and yellow LEDs, which the researchers noted suggested an effective suppression in quantum confined Star effect in their LEDs.

EL Emission photos of (a) green, (b) yellow-green, (c) yellow, and (d) amber LEDs, taken at 5, 20, and 100 mA. (Photo courtesy of Applied Physics Letter)

On-wafer measurements yield a linear increase in the light output with the current, and external quantum efficiency demonstrated a significant improvement in the efficiency-droop compared to commercial c-plane LED. Electro-luminescence polarization measurements show a polarization ratio of about 25% in the semipolar LEDs.

The full report in Applied Physics Letter can be viewed here.

Disclaimers of Warranties
1. The website does not warrant the following:
1.1 The services from the website meets your requirement;
1.2 The accuracy, completeness, or timeliness of the service;
1.3 The accuracy, reliability of conclusions drawn from using the service;
1.4 The accuracy, completeness, or timeliness, or security of any information that you download from the website
2. The services provided by the website is intended for your reference only. The website shall be not be responsible for investment decisions, damages, or other losses resulting from use of the website or the information contained therein<
Proprietary Rights
You may not reproduce, modify, create derivative works from, display, perform, publish, distribute, disseminate, broadcast or circulate to any third party, any materials contained on the services without the express prior written consent of the website or its legal owner.

Tokushima, Japan - 6 March 2024: Nichia, the world's largest LED manufacturer and inventor of the high-brightness blue and white LED, has started mass production of the new UV-B (308nm) and UV-A (330nm) LEDs in its popular 434 Series packa... READ MORE

New XLamp® S Line LEDs enhance growth, last longer, lower energy costs Horticulture and other forms of agricultural lighting require application-tuned ratios of spectral content, high efficacy and long lifetimes. Whether you are interested... READ MORE