Two-dimensional exciton behavior in GaN nanocolumns grown by molecular-beam epitaxy

Na, Jong H.; Taylor, Robert A.; Rice, James H.; Robinson, James W.; Lee, Kwan H.; Park, Young S.; Park, Chang M.; Kang, Tae W.
March 2005
Applied Physics Letters;3/21/2005, Vol. 86 Issue 12, p123102
Academic Journal
We have investigated the behavior of excitons in GaN nanocolumns using time-integrated and time-resolved micro-photoluminescence measurements. In the weak confinement limit, the model of fractional-dimensional space gives an intermediate dimensionality of 2.14 for GaN nanocolumns, with an average diameter of 80 nm. Enhanced exciton and donor binding energies are deduced from a fractional-dimensional model and a phenomenological description. Time-integrated photoluminescence spectra as a function of temperature show a curved emission shift. Recombination dynamics are deduced from the temperature dependence of the PL efficiency and decay times.


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