Superlattice Electron Blocking Layer Boosts UV LEDs Efficiency

News Source: 


WHU team shows improved quantum efficiency of UV LEDs by introducing AlInGaN/AlGaN superlattice electron blocking layer (SEBL)

A research team led by Shengjun Zhou at Wuhan University has reported a special design of electron blocking layer (EBL) to improve the efficiency of ultraviolet light-emitting diodes (UV LEDs). They proposed an AlInGaN/AlGaN superlattice electron blocking layer (SEBL) to boost quantum efficiency of ~371 nm UV LEDs.

The UV LEDs have gained growing interest for tremendous applications, such as lithography, medical curing, 3D printing, gas sensing, plant lighting, and pumping sources of white LEDs. However, the relatively lower quantum efficiency of UV LEDs hinders their further widespread usage, compared with the visible counterparts.

The researchers have demonstrated that the introduction of AlInGaN/AlGaN SEBL can achieve high-efficiency UV LEDs by energy band modulation. The less tilted energy band of quantum wells due to strain relaxation effect of SEBL can mitigate the separation of carrier wave functions. The increased effective barrier height for electrons and notches in the conduction band of SEBL will effectively suppress the electron leakage.

Furthermore, the spikes in the valance band of SEBL can attract holes, thereby facilitating hole injection into the active region. Benefitting from these significant advantages, the UV LED with AlInGaN/AlGaN SEBL exhibits a 21 percent higher light output power and smaller forward voltage, as compared to the UV LED with AlInGaN EBL.

The pictures above show (a) Cross-sectional TEM images of UV LEDs structure. (b) EL image of UV LED chip at 60 mA.

‘Rational superlattice electron blocking layer design for boosting the quantum efficiency of 371 nm ultraviolet light-emitting diodes' by Peng Du et al, IEEE Transactions on Electron Devices, 2021, doi: 10.1109/TED.2021.3118990.

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.

NF2W585AR-P8 is a dual function LED that provides both white light and high doses of energy geared for inactivation of various prevalent bacteria. With a 405nm wavelength1 die known to be effective in sterilization, this LED can be used t... READ MORE

  The 5050 LED is replacing the 3535 LED, which has long been the leader in the outdoor lighting market. The existing ceramic-based 3535 has excellent reliability but is expensive. At present, the 5050 LED, which has achieved remarkable p... READ MORE