Author/Authors :
ESMAEILI، M نويسنده 1Department of Basic Science, Islamic Azad University, Damghan Branch, Damghan, I. R. of Iran , , HARATIZADEH، H نويسنده Department of Physics, Shahrood University of Technology, 3619995161, P.O. Box 316, Shahrood, I. R. of Iran , , GHOLAMI، M نويسنده 1Department of Basic Science, Islamic Azad University, Damghan Branch, Damghan, I. R. of Iran , , MONEMAR، B نويسنده 3Department of Physics, Chemistry and Biology, Linkoping University, SE-581 581 83 Linkoping, Sweden ,
Abstract :
Due to many important applications, the group III-Nitride semiconductors have recently attracted
remarkable attention among semiconductor researchers and engineers. In this paper, we report on the impact
of extrinsic and temporal carriers on the screening of polarization internal fields. The optical efficiency of
GaN/AlGaN multiple quantum well (MQW) nanostructures were studied by means of photoluminescence
(PL) and time-resolved PL measurements. Extrinsic carriers come from Si doping in the barriers, while
temporal carriers originate when the samples are excited by laser beam. The emission peaks of MQWs in PL
spectra of the undoped and low-doped samples show a shift towards higher energy levels as excitation
intensity increases, while the other samples do not exhibit such a phenomenon due to the dominance of the
extrinsic carriers. The transient data confirm the results of the PL measurements.
