009 resulted in a decrease in hole effective mass. In order to understand the unpredicted N dependence of hole effective mass, both compressive strain- and confinement-induced effects should be considered. With increasing N content, compressive strain decreases and confinement becomes stronger due to the redshift of the bandgap. Stronger confinement decreases the hole effective mass, while less compressive strain increases the hole mass. Moreover, a reduction of the hole concentration decreases the hole effective mass due to change of the valence band non-parabolicity. Therefore, the value of hole effective mass

depends on several competing mechanisms. We can conclude that in our N-containing samples, stronger confinement selleck chemical and reduced 2D hole density (see Table 2) are the dominant mechanisms, affecting hole effective mass. A more detailed study of N dependency of hole effective mass and effect of thermal annealing on hole effective mass in these samples can be found in our previous paper [14]. Table 2 Effective mass, 2D carrier density, and Fermi energy values found from analysis of SdH oscillations Samples n 2D(×1012 cm-2) (E F-E1) (meV) p-type n-type p-type n-type Ga0.62In0.38As As-grown 1.38 2.02 36.8 113.8 Annealed (60 s)

PF2341066 1.34 1.95 41.5 101.7 Annealed (600 s) – 1.92 – 90.9 Ga0.62In0.38 N0.009As0.991 As-grown 1.18 2.30 52.7 99.5 Annealed (60 s) 1.16 2.29 52.0 82.1 Annealed (600 s) 1.17 2.32 52.8 83.1 Ga0.62In0.38 N0.012As0.988 As-grown 1.20 2.50 40.0 0.0686 Annealed (60 s) 1.06 2.59 55.5 0.0699 Annealed (600 s) – 2.71 – 0.0788 The analysis of SdH is also useful to obtain both 2D carrier density and Isoconazole Fermi energy. A plot of the reciprocal magnetic field versus the peak number n gives the period of the SdH oscillations, Δ(1/B). The 2D carrier density and the Fermi energy can be calculated from the obtained period of SdH oscillations using [18, 22, 24] (7) where

E F - E 1 is the energy difference between the Fermi level and occupied first subband level; m*, effective mass; and n 2D, 2D carrier density. Figure 3 shows the plot of 1/B i versus n and the slope of the lines for n- and p-type samples with 0.9% nitrogen composition. The fact that the plots have the same slope is an indication of only one occupied subband. We obtained that slopes are independent of temperature. Using the slope of the plot, both 2D carrier density and Fermi energy are calculated and tabulated in Table 2. Figure 3 Plot of 1/ B i versus n and the slope of the lines for n- and p-type samples. The reciprocal magnetic field (1/B) versus peak number (n) of SdH oscillations for as-grown p- and n-type samples with y = 0.009. Although all samples were doped with the same doping concentration, among n-type samples, among n-type samples, N-free ones have the lowest electron density.