Figure 1

MR for devices with $\alpha \mathrm{\text{−}}6\mathrm{T}$ layers of varying thickness. Panels (a)–(c) show MR at 300 K for devices with $\alpha \mathrm{\text{−}}6\mathrm{T}$ layers of (a) 50 nm, (b) 100 nm, and (c) 200 nm, while panels (d)–(f) show MR at 5 K for layer thicknesses of (d) 50 nm, (e) 100 nm, and (f) 200 nm. Shown in (a) and (c) are examples of MR inversion with applied bias, from negative to positive MR for (a) and vice versa for (c). The magnitude of the MR in (d) and (e) decreases as bias is increased. The MR in (f) is a mixture of positive and negative behavior that becomes strictly negative as bias increases.Reuse & Permissions

Figure 2

(a) Schematic plot of curves corresponding to low (curve 1), intermediate (curve 2), and high (curve 3) values of ${\mu }_c$, where ${\mu }_c$ is the peak of each curve. The shaded region indicates the accessible range of ${\mu }_r$ ($\Delta {\mu }_r$). The portion of a given curve within the shaded region determines whether the MR will be negative, positive, or a mixture. (b) Plot of the critical recombination mobility ${\mu }_c$ as a function of applied voltage $V$ [Eq. (3)]. The different regions I, II, and III indicate where the function has a positive slope, a maximum, or a negative slope, respectively. The parameters voltage, temperature, and layer thickness determine the curve in which the device operates.Reuse & Permissions