Jm. Myoung et al., Depth-resolved cathodoluminescence of III-V nitride films grown by plasma-assisted molecular beam epitaxy, JPN J A P 1, 40(2A), 2001, pp. 476-479
The luminescence properties of m-V nitride films (an undoped GaN, an undope
d GaN/Al0.2Ca0.8N multiquantum well, and a p-type Mg-doped GaN films) were
investigated using the depth-resolved cathodoluminescence (CL) spectroscopy
. From the low- and room-temperature Ct of the undoped GaN and GaN/AlGaN MQ
W films, an emission at 2.9 eV was found with the longer penetration depth
and is attributed to the higher density of dislocations at the interface be
tween the film and the substrate. In order to explain the depth-resolved Ct
of the Mg-doped GaN film, the configuration coordinate model is proposed o
n the basis of the local strain near the Mg impurities. This model demonstr
ates that local strain may play a crucial role in controlling the radiative
efficiency, line width, and peak position of the luminescence from the fil
m.