Effects of Si doping position on the emission energy and recombination dynamics of GaN/AlGaN multiple quantum wells

Hamid Haratizadeh 3Bo Monemar 1H. Amano 2

1. Linköping University, Dept. of Physics and Meas. Techn., Linkoping, Sweden
2. Department of Electrical and Electronic Engineering, Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya 1-501, Japan
3. Shahrood University of Technology, University Bolvd., Shahrood 3619995161, Iran


The effects of Si doping on the emission energy and recombination dynamics in a set of GaN/Al0.07Ga0.93N multiple quantum wells (MQWs) samples with different position of the dopant layer were studied by means of photoluminescence (PL) and time-resolved PL measurements. When the doping is in the barrier and in both barrier and well, the MQW emission appears above the GaN bandgap, while the sample doped in the well shows a redshifted emission. The redshift is attributed to the self-energy shift of the electron states due to the correlated motion of the electrons exposed to the fluctuating potential of the donor ions. At low temperature a longer PL decay time, 760 ps, was measured for the sample doped in the well, a factor two longer than for the barrier doped case. The difference is explained by the effect of interplay of free carriers and ions on the screening of the polarization field in these doped structures.

PACS: 78.47.+p, 78.55.Cr, 78.67.De



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Presentation: oral at E-MRS Fall Meeting 2005, Symposium A, by Hamid Haratizadeh
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-05-22 13:06
Revised:   2009-06-07 00:44