In two-dimensional (2D) materials, such as black phosphorus, the hysteresis attributed to surface and interfacial disorder can severely limit applications in electronics. In this work, we characterize the hysteresis in Al2O3-encapsulated black phosphorous samples by studying conductivity switching transients in response to an applied step gate bias. Using the dispersive diffusion model for relaxation in disordered systems, the so-called bimolecular and unimolecular recombination limits were observed in low-disorder pristine and high-disorder oxidized BP samples, respectively. Two different heavy-tail lineshapes ( the algebraic decay and the stretched exponential relaxation ) were clearly distinguished in the low- and high-disorder limits, respectively. The parameterization of these transients allows temperature dependence of the line-fit parameters to be tracked. If interpreted under the continuous time random walk model, the observed temperature dependence of the dispersion parameter beta would result from a disorder-induced tail of localized trap states.

Date Published: 8 March 2019
PDF
Proc. SPIE 10926, Quantum Sensing and Nano Electronics and Photonics XVI, 109262B (8 March 2019); doi: 10.1117/12.2514105

Published in SPIE Proceedings Vol. 10926:
Quantum Sensing and Nano Electronics and Photonics XVI
Manijeh Razeghi; Jay S. Lewis; Eric Tournié; Giti A. Khodaparast, Editor(s)