Significant Mobility Enhancement in Extremely Thin Highly Doped ZnO Films

Authors

David C. Look, Wright State University - Main CampusFollow
Eric R. Heller
Yu-Feng Yao
C. C. Yang

Document Type

Article

Publication Date

2015

Abstract

Highly Ga-doped ZnO (GZO) films of thicknesses d = 5, 25, 50, and 300 nm, grown on 160-nmZnO buffer layers by molecular beam epitaxy, had 294-K Hall-effect mobilities μH of 64.1, 43.4, 37.0, and 34.2 cm²/V-s, respectively. This extremely unusual ordering of μH vs d is explained by the existence of a very high-mobility Debye tail in the ZnO, arising from the large Fermi-level mismatch between the GZO and the ZnO. Scattering theory in conjunction with Poisson analysis predicts a Debye-tail mobility of 206 cm²/V-s at the interface (z = d), falling to 58 cm²/V-s at z = d + 2 nm. Excellent fits to μH vs d and sheet concentration ns vs d are obtained with no adjustable parameters.

Repository Citation

Look, D. C., Heller, E. R., Yao, Y., & Yang, C. C. (2015). Significant Mobility Enhancement in Extremely Thin Highly Doped ZnO Films. Applied Physics Letters, 106, 152102.
https://corescholar.libraries.wright.edu/physics/901

DOI

10.1063/1.4917561