WANG Hai-long, ZHU Hai-jun, FENG Song-lin, NING Dong, WANG Hui, WANG Xiao-dong, JIANG De-sheng. Photoluminescence in Be-doped Self-organized InAs Quantum Dots[J]. Chinese Journal of Luminescence, 2000,21(1): 20-23
WANG Hai-long, ZHU Hai-jun, FENG Song-lin, NING Dong, WANG Hui, WANG Xiao-dong, JIANG De-sheng. Photoluminescence in Be-doped Self-organized InAs Quantum Dots[J]. Chinese Journal of Luminescence, 2000,21(1): 20-23DOI:
The photoluminescence (PL) in directly Be doped self organized InAs quantum dots (QDs) grown by molecular beam epitaxy has been firstly studied systematically. The samples of single layer QDs were undoped and directly doped with Be of 1×10
17
cm
-3
5×10
17
cm
-3
and 2×10
18
cm
-3
in 2.5ml InAs layer
respectively. The samples of multi-layer QDs were undoped and doped with Be of 3×10
16
cm
-3
homogeneously. When the doping level is low
a decrease in line width and a little blue shift in peak are observed in PL. However
when the doping level is high
the uniformity and photoluminescence peak intensity of QDs will be decreased. With doping
Be atoms act as the nucleation centers in the formation of QDs. Due to doping induced nucleation centers
there are more nucleation centers in the doped samples. The size fluctuation of QDs becomes smaller. Hence the line width of PL spectra will decrease. There will be more and more nucleation centers with the increasing of doping level. So more and more QDs will be formed. With increasing the number of QDs
there will be amalgamation between different small QDs. So the size fluctuation of QDs becomes larger
which will cause the increase in line-width and decrease in peak intensity in PL. Another reason for the phenomena may be due to the incorporation of nonradiative impurities with a higher level doping. Thus
appropriate doping maybe helpful to the formation of uniform QDs. However
unduly doping seems to lower the quality of QDs. The work will be very meaningful for the fabrication of self organized InAs quantum dots devices.