AlN/GaN Digital Alloy for Mid- and Deep-Ultraviolet Optoelectronics
Wei Sun1, Chee-Keong Tan2,3, Nelson Tansu4
1Center for Photonics and Nanoelectronics, Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, 18015, USA. wes212@lehigh.edu.
Scientific Reports
|September 21, 2017
Summary
AlN/GaN digital alloys offer tunable energy gaps for mid- and deep-ultraviolet (UV) devices. This nanostructure enhances electron-hole overlap, boosting internal quantum efficiency for high-performance UV applications.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Optoelectronics
Background:
- AlN/GaN digital alloys (DA) are superlattice nanostructures with ultra-thin AlN barriers and GaN wells.
- These structures are crucial for developing mid- and deep-ultraviolet (UV) optoelectronic devices.
Purpose of the Study:
- To comprehensively investigate the electronic and optoelectronic properties of AlN/GaN DA.
- To explore the potential of AlN/GaN DA for mid- and deep-UV applications.
Main Methods:
- Numerical analysis of miniband engineering by varying AlN barrier and GaN well thicknesses.
- Band structure calculations to determine valence subband rearrangement.
- Analysis of electron-hole wavefunction overlap and optical absorption properties.
Main Results:
- Engineered effective energy gap from ~3.97 eV to ~5.24 eV.
- Rearranged valence subbands with heavy-hole miniband as the top subband, enabling transverse-electric polarized emission.
- Remarkable enhancement of electron-hole wavefunction overlap up to 97%.
Conclusions:
- AlN/GaN DA exhibits tunable electronic and optical properties for mid- and deep-UV applications.
- The structure shows significant potential for improving internal quantum efficiency in UV devices.
- AlN/GaN DA is a promising active region design for high-efficiency mid- and deep-UV optoelectronics.
