Site-selectively growth and small footprint on Si techniques make GaN-based core-shell nanowires to be potential building blocks for fabricating devices such as laser diodes, solar cells, and field-effect transistors.
Drift is fundamental in electronic devices, and can eventually determine their performance. It is well known that the optical phonons (OPs) play the main role on the electron mobility (EM) at room temperature. In this talk, we report a theoretically study on the OPs-limited EM in InxGa1-xN/GaN CSNWs and its ternary and size effects, based on the theory of force-balance and energy-balance equations.1 The results show that the quasi-confined OPs are much more important than the interface (IF) and propagating (PR) OPs. This is caused by the strong quantum confinement effects that can push the electrons to distribute in the core of InGaN layer. The total EM reaches its peak value at a certain composition. It is the critical composition for PR OPs transforming to IF OPs due to the anisotropy phonon dispersions in wurtzite nitrides. It is also found that EM increases as the core radius due to a weakened scattering by confined OPs. The total EM shows an obvious enhancement when decreases the temperature or increases the electron density.2 These theoretical results are expected to be helpful for design of CSNWs structure devices.
1 X. L. Lei and C. S. Ting, Phys. Rev. B 30, 4809 (1984)
2 W. H. Liu, Y. Qu and S. L. Ban, J. Appl. Phys. 122, 115104 (2017).