Table 1

Simulation parameters for the PL maps and spectra of chirped QDM bilayers

Type I - straddled

Type II - staggered

Type III - broken-gap

I_i

E_i

FWHM

η_i

I_i

E_i

FWHM

η_i

I_i

E_i

FWHM

η_i

(eV)

(meV)

(eV)

(meV)

(eV)

(meV)

QDM₂

sQD₂

0.071

1.114*

51.8*

1.1-1.9

0.044

1.213*

49.5*

1-1.8

0.7

1.220*

65.9*

1.0-2

cQD₂

0.358

1.085

28.3

1.0-1.6

0.591

1.120

40.0

1-1.4

0.7

1.170

33.0

1.1-2

QDM₁

sQD₁

0.094

1.214*

77.7*

1.1-1.9

0.315

1.160*

53.0*

1-1.8

1.0

1.121

42.4

1.1-2

cQD₁

1.000

1.048

30.6

1.0-1.6

1.000

1.077

40.0

1-1.4

1.0

1.078

33.0

1.1-2

20-K peak energy position E_i, relative intensity I_i, and FWHM of cQDs and sQDs ensembles of types I, II, and III chirped QDM bilayers extracted from Figure 4a,b,c, respectively. The ideality factor ηi varies linearly with temperature from the lower limit value at 20 K to the upper limit value at 300 K. Subscripts 1 and 2 represent the lower and upper QDM layers, respectively. E_i's temperature dependency follows Varshni's equation unless marked by an asterisk where it instead follows the sigmoidal behavior. FWHM is assumed constant unless marked by an asterisk where it follows the anomalous temperature behavior. The FWHM is related to the standard deviation of the Gaussian distribution or the broadening parameter Γ through the relationship: FWHM (meV) = 1,665.11 × Γ.

Patanasemakul et al. Nanoscale Research Letters 2012 7:207   doi:10.1186/1556-276X-7-207