2015 journal article

High internal quantum efficiency in AlGaN multiple quantum wells grown on bulk AlN substrates

APPLIED PHYSICS LETTERS, 106(14).

By: Z. Bryan n, I. Bryan n, J. Xie*, S. Mita*, Z. Sitar n & R. Collazo n

co-author countries: United States of America 🇺🇸
Source: Web Of Science
Added: August 6, 2018

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.