Surface-plasmon-enhanced deep-UV light emitting diodes based on AlGaN multi-quantum wells
Na Gao1, Kai Huang, Jinchai Li
1Department of Physics, Fujian Provincial Key Laboratory of Semiconductor Materials and Application, Xiamen University, Xiamen 361005, China.
Scientific Reports
|November 15, 2012
Summary
Researchers developed aluminum gallium nitride (AlGaN)-based deep-ultraviolet light-emitting diodes (LEDs) using an aluminum thin layer. This layer significantly boosts light extraction efficiency (LEE) through plasmon coupling, enhancing deep-UV LED performance.
Area of Science:
- Materials Science
- Optoelectronics
- Solid-State Physics
Background:
- Deep-ultraviolet light-emitting diodes (LEDs) are crucial for applications like sterilization and sensing.
- Improving light extraction efficiency (LEE) is a key challenge in AlGaN-based deep-UV LED development.
- Surface plasmon coupling offers a potential mechanism to enhance light emission.
Purpose of the Study:
- To develop AlGaN-based deep-UV LEDs with enhanced light extraction efficiency.
- To investigate the effect of an aluminum (Al) thin layer on LED performance.
- To understand the underlying mechanism of emission enhancement.
Main Methods:
- Fabrication of AlGaN-based deep-UV LEDs with an integrated Al thin layer.
- Photoluminescence (PL) intensity measurements at 294 nm.
- Cathodoluminescence (CL) measurements to assess internal quantum efficiency (IQE).
- Analysis of surface plasmon-transverse magnetic (TM) wave coupling.
Main Results:
- A 217% enhancement in peak photoluminescence intensity was observed.
- Internal quantum efficiency was not improved by the Al layer coating.
- Emission enhancement is attributed to increased LEE via surface plasmon-TM wave coupling.
- Higher Al content in Al(x)Ga(1-x)N wells correlated with increased enhancement ratio.
Conclusions:
- The Al thin layer effectively enhances light extraction efficiency in deep-UV LEDs.
- Surface plasmon-TM wave coupling is the primary mechanism for emission enhancement.
- Optimizing Al content in the quantum wells can further improve LED performance.
