Ja. Yater et al., PHOTOLUMINESCENCE OF QUANTUM DOTS FABRICATED USING TUNGSTEN STRESSORS, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 13(6), 1995, pp. 2284-2288
Strain modulation of a semiconductor band gap spatially confines excit
ons in a near-surface GaAs/AlGaAs quatum well. mie report photolumines
cence (PL) results of quantum dot arrays fabricated using tungsten str
essors. Excitons are cofined in a 35 meV potential well under 100 nm d
ot stressors, which is 2.4 times deeper than that observed using 100 n
m carbon stressors. Such a confinement potential corresponds to quantu
m dot energy level splittings of approximately 7 meV. Arrays of dots a
re studied, each with individual stressors of a different size ranging
from 100 to 800 nm. The lateral potential well depth, as measured by
the red shift in PL signal, is dependent on the stresser width and thi
ckness in a well-understood manner. The integrated PL signal from the
dots increases with increasing temperature, indicating increased effic
iency of trapping of excitons from the quantum well into the quantum d
ots. Interpretation of excitation spectra, and observation of higher e
nergy levels, are complicated by the details of the strain pattern and
the near-field coupling of radiation between the metallic stressors a
nd the quantum well. (C) 1995 American Vacuum Society.