Carrier dynamics in epilayers and nanocolumns of ternary AlGaN with a tunable bandgap
Journal
IOP Conference Series: Materials Science and Engineering
Journal Volume
38
Journal Issue
1
Pages
1-5
Date Issued
2012
Author(s)
Aleksiejunas, R.
Ščajev, P.
Nargelas, S.
Miasojedovas, S.
Jarašiunas, K.
Trinkler, L.
Grigorjeva, J.
Berzina, B.
Chen, K.H.
Chen, Y.T.
Chen, M.W.
Abstract
We apply several optical time-resolved techniques to investigate the dynamics of excess carriers in AlxGa1−xN nanocolumns grown on (111) silicon substrates and in thick AlxGa1−xN epitaxial layers deposited on sapphire. We demonstrate that carrier lifetime drops in nanocolumns by several times if compared to epilayers with similar Al content; in addition, recombination rate displays a strong nonlinearity on excitation. On the other hand, carrier localization effects observed in the epilayers completely disappear in nanocolumns.
Publisher
Institute of Physics
Type
conference paper