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Improved infrared photoluminescence characteristics from circularly ordered self-assembled Ge islands.

Das S, Das K, Singha RK, Manna S, Dhar A, Ray SK, Raychaudhuri AK - Nanoscale Res Lett (2011)

Bottom Line: The formation of circularly ordered Ge-islands on Si(001) has been achieved because of nonuniform strain field around the periphery of the holes patterned by focused ion beam in combination with a self-assembled growth using molecular beam epitaxy.The photoluminescence (PL) spectra obtained from patterned areas (i.e., ordered islands) show a significant signal enhancement, which sustained till 200 K, without any vertical stacking of islands.The origin of two activation energies in temperature-dependent PL spectra of the ordered islands has been explained in detail.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India. physkr@phy.iitkgp.ernet.in.

ABSTRACT
The formation of circularly ordered Ge-islands on Si(001) has been achieved because of nonuniform strain field around the periphery of the holes patterned by focused ion beam in combination with a self-assembled growth using molecular beam epitaxy. The photoluminescence (PL) spectra obtained from patterned areas (i.e., ordered islands) show a significant signal enhancement, which sustained till 200 K, without any vertical stacking of islands. The origin of two activation energies in temperature-dependent PL spectra of the ordered islands has been explained in detail.

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Temperature-dependent integrated PL intensity of Ge islands grown on (a) unpatterned substrate, and (b) patterned substrate (500-nm pitch). Solid lines show the fitting with one and two activation energies for (a) unpatterned and (b) patterned (500-nm pitch) substrates, respectively.
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Figure 6: Temperature-dependent integrated PL intensity of Ge islands grown on (a) unpatterned substrate, and (b) patterned substrate (500-nm pitch). Solid lines show the fitting with one and two activation energies for (a) unpatterned and (b) patterned (500-nm pitch) substrates, respectively.

Mentions: For better understanding of the thermal-quenching mechanism, we have plotted the variation of PL intensity as a function of 1000/T in Figure 6a,b for unpatterned and patterned samples, respectively. The PL intensity temperature dependences is fitted by a standard equation [21](2)


Improved infrared photoluminescence characteristics from circularly ordered self-assembled Ge islands.

Das S, Das K, Singha RK, Manna S, Dhar A, Ray SK, Raychaudhuri AK - Nanoscale Res Lett (2011)

Temperature-dependent integrated PL intensity of Ge islands grown on (a) unpatterned substrate, and (b) patterned substrate (500-nm pitch). Solid lines show the fitting with one and two activation energies for (a) unpatterned and (b) patterned (500-nm pitch) substrates, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211512&req=5

Figure 6: Temperature-dependent integrated PL intensity of Ge islands grown on (a) unpatterned substrate, and (b) patterned substrate (500-nm pitch). Solid lines show the fitting with one and two activation energies for (a) unpatterned and (b) patterned (500-nm pitch) substrates, respectively.
Mentions: For better understanding of the thermal-quenching mechanism, we have plotted the variation of PL intensity as a function of 1000/T in Figure 6a,b for unpatterned and patterned samples, respectively. The PL intensity temperature dependences is fitted by a standard equation [21](2)

Bottom Line: The formation of circularly ordered Ge-islands on Si(001) has been achieved because of nonuniform strain field around the periphery of the holes patterned by focused ion beam in combination with a self-assembled growth using molecular beam epitaxy.The photoluminescence (PL) spectra obtained from patterned areas (i.e., ordered islands) show a significant signal enhancement, which sustained till 200 K, without any vertical stacking of islands.The origin of two activation energies in temperature-dependent PL spectra of the ordered islands has been explained in detail.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India. physkr@phy.iitkgp.ernet.in.

ABSTRACT
The formation of circularly ordered Ge-islands on Si(001) has been achieved because of nonuniform strain field around the periphery of the holes patterned by focused ion beam in combination with a self-assembled growth using molecular beam epitaxy. The photoluminescence (PL) spectra obtained from patterned areas (i.e., ordered islands) show a significant signal enhancement, which sustained till 200 K, without any vertical stacking of islands. The origin of two activation energies in temperature-dependent PL spectra of the ordered islands has been explained in detail.

No MeSH data available.


Related in: MedlinePlus