High internal quantum efficiency in AlGaN multiple quantum wells grown on bulk AlN substrates
Abstract
The internal quantum efficiency (IQE) of Al0.55Ga0.45N/AlN and Al0.55Ga0.45N/Al0.85Ga0.15N UVC MQW structures was analyzed. The use of bulk AlN substrates enabled us to undoubtedly distinguish the effect of growth conditions, such as V/III ratio, on the optical quality of AlGaN based MQWs from the influence of dislocations. At a high V/III ratio, a record high IQE of ∼80% at a carrier density of 1018 cm−3 was achieved at ∼258 nm. The high IQE was correlated with the decrease of the non-radiative coefficient A and a reduction of midgap defect luminescence, all suggesting that, in addition to dislocations, point defects are another major factor that strongly influences optical quality of AlGaN MQW structures.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 06, 2015
- Source ID
- 10.1063/1.4917540
Entities
People
- Isaac Bryan
- Jinqiao Xie
- Ramón Collazo
- Seiji Mita
- Zachary Bryan
- Zlatko Sitar
Organizations
- Army Research Office
- National Science Foundation
- North Carolina State University