Fig. 4
From: Mapping the band structure of GeSbTe phase change alloys around the Fermi level
Charge carrier density neff and curvature parameter \(m^ \star\) deduced from ARPES. a EDC at k = (0.0, 0.13, 2.73) Å−1 (black dots) with fit curve (red) consisting of two Voigt peaks (p1 = green, p2 = blue) multiplied by the Fermi distribution function f0 (E, T = 300 K) (thin red line); inset: zoom around \(E_{\mathrm{F}}^{{\mathrm{PES}}}\) displaying peak tails, after scaling each peak area to unity; only the colored tail of peak 1 (marked α1) contributes to neff,1; b EMC at kz = 2.73 Å−1 with marked peak positions p1 (green dots) and p2 (blue dots) resulting from fits of EDCs as in a; parabolic fits to these points (accordingly colored full lines), used to determine \(m^ \star\), are added; c histogram of resulting \(m^ \star {\mathrm{/}}m_{\mathrm{e}}\) belonging to the band of p1 using 90 different azimuths in (k x , k y ) direction for 29 different k z -values; errors for individual \(m^ \star {\mathrm{/}}m_{\mathrm{e}}\) are about the bin width; d red full line: neff as calculated from the ARPES data according to Eq. (2) for a hypothetically varying EF with respect to the measured \(E_{\mathrm{F}}^{{\mathrm{PES}}}\); different contributions from p1 (green full line) and p2 (blue full line) are labeled; error intervals are depicted by correspondingly colored dashed lines; charge carrier densities from Hall measurements (neff,H) of identically prepared GST films are added as a gray box; inset: α j (k) (relative part of the Voigt peak p j at k above \(E_{\mathrm{F}}^{{\mathrm{PES}}}\)) for the EMC of b
