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Photoluminescence characteristics of Cd1-xMnxTe single crystals grown by the vertical Bridgman method.

Hwang Y, Um Y, Park H - Nanoscale Res Lett (2012)

Bottom Line: The near-band-edge emissions of neutral acceptor-bound excitons (labeled as L1) were systematically investigated as a function of temperature and of alloy composition.The parameters that describe the temperature variation of the energy were evaluated by the semiempirical Varshni relation.The activation energies of thermal quenching were obtained for the L1 peak from the temperature dependence of the bound exciton peaks and were found to decrease with increasing Mn concentration.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, University of Ulsan, Ulsan, 680-749, South Korea. yhum@ulsan.ac.kr.

ABSTRACT
In this paper, we report a systematic investigation of band-edge photoluminescence for Cd1-xMnxTe crystals grown by the vertical Bridgman method. The near-band-edge emissions of neutral acceptor-bound excitons (labeled as L1) were systematically investigated as a function of temperature and of alloy composition. The parameters that describe the temperature variation of the energy were evaluated by the semiempirical Varshni relation. From the temperature dependence of the full width at half maximum of the L1 emission line, the broadening factors Γ(T) were determined from the fit to the data. The activation energies of thermal quenching were obtained for the L1 peak from the temperature dependence of the bound exciton peaks and were found to decrease with increasing Mn concentration.

No MeSH data available.


Related in: MedlinePlus

Photoluminescence spectra observed at 12 K. The spectra was observed for a series of CMT crystals with different Mn concentrations x. The inset displays typical PL spectra at 300 K.
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Figure 1: Photoluminescence spectra observed at 12 K. The spectra was observed for a series of CMT crystals with different Mn concentrations x. The inset displays typical PL spectra at 300 K.

Mentions: Figure 1 shows the PL spectra at 12 K and 300 K taken on the CMT crystals for Mn concentration from x = 0.0 to 0.2. In DMSs, the strong sp-d exchange interaction between carriers and localized magnetic ions gives rise to the formation of a magnetic polaron and causes an energy shift as a result. However, we only considered the behavior of the exciton peak with temperature and composition without taking the formation of a magnetic polaron into account because our temperature was slightly high to show the bound magnetic polaron in the PL spectra, and there was no applied magnetic field. The PL spectra are dominated by exciton peaks, i.e., there is no noticeable luminescence associated with self-activated or other deep centers. The band-edge emission peaks of a CdTe crystal are similar to those found in the PL spectra reported by other investigators [6,7], and it will therefore be convenient to use our results for CdTe as a point of departure.


Photoluminescence characteristics of Cd1-xMnxTe single crystals grown by the vertical Bridgman method.

Hwang Y, Um Y, Park H - Nanoscale Res Lett (2012)

Photoluminescence spectra observed at 12 K. The spectra was observed for a series of CMT crystals with different Mn concentrations x. The inset displays typical PL spectra at 300 K.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3275455&req=5

Figure 1: Photoluminescence spectra observed at 12 K. The spectra was observed for a series of CMT crystals with different Mn concentrations x. The inset displays typical PL spectra at 300 K.
Mentions: Figure 1 shows the PL spectra at 12 K and 300 K taken on the CMT crystals for Mn concentration from x = 0.0 to 0.2. In DMSs, the strong sp-d exchange interaction between carriers and localized magnetic ions gives rise to the formation of a magnetic polaron and causes an energy shift as a result. However, we only considered the behavior of the exciton peak with temperature and composition without taking the formation of a magnetic polaron into account because our temperature was slightly high to show the bound magnetic polaron in the PL spectra, and there was no applied magnetic field. The PL spectra are dominated by exciton peaks, i.e., there is no noticeable luminescence associated with self-activated or other deep centers. The band-edge emission peaks of a CdTe crystal are similar to those found in the PL spectra reported by other investigators [6,7], and it will therefore be convenient to use our results for CdTe as a point of departure.

Bottom Line: The near-band-edge emissions of neutral acceptor-bound excitons (labeled as L1) were systematically investigated as a function of temperature and of alloy composition.The parameters that describe the temperature variation of the energy were evaluated by the semiempirical Varshni relation.The activation energies of thermal quenching were obtained for the L1 peak from the temperature dependence of the bound exciton peaks and were found to decrease with increasing Mn concentration.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, University of Ulsan, Ulsan, 680-749, South Korea. yhum@ulsan.ac.kr.

ABSTRACT
In this paper, we report a systematic investigation of band-edge photoluminescence for Cd1-xMnxTe crystals grown by the vertical Bridgman method. The near-band-edge emissions of neutral acceptor-bound excitons (labeled as L1) were systematically investigated as a function of temperature and of alloy composition. The parameters that describe the temperature variation of the energy were evaluated by the semiempirical Varshni relation. From the temperature dependence of the full width at half maximum of the L1 emission line, the broadening factors Γ(T) were determined from the fit to the data. The activation energies of thermal quenching were obtained for the L1 peak from the temperature dependence of the bound exciton peaks and were found to decrease with increasing Mn concentration.

No MeSH data available.


Related in: MedlinePlus