Projects per year
Black phosphorus (BP) is an emerging 2D semiconducting material with great potential for nanoelectronic and nanophotonic applications, especially owing to its unique anisotropic electrical and optical properties. Many theoretical studies have predicted the anisotropic optical properties of BP, but the direct experimental quantification remains challenging. The difficulties stem from the ease of BP's degradation when exposed to air in ambient conditions, and from the indirect nature of conventional approaches that are subject to large measurement uncertainties. This work reports a direct investigation of the birefringent optical constants of micrometer-thick BP samples with picosecond (ps) interferometry, over the wavelength range from 780 to 890 nm. In this ps-interferometry approach, an ultrathin (5 nm) platinum layer for launching acoustic waves naturally protects the BP flake from degradation. The birefringent optical constants of BP for light polarization along the two primary crystalline orientations, zigzag and armchair, are directly obtained via fitting the attenuated Brillouin scattering signals. A biexponential model is further proposed to analyze the Brillouin scattering signals for a random incident light polarization. The BP experimental results and the associated measurement sensitivity analysis demonstrate the reliability and accuracy of the ps-interferometry approach for capturing the polarization-dependent optical properties of birefringent materials.
Bibliographical noteFunding Information:
This work was supported by the National Science Foundation (NSF) through the University of Minnesota MRSEC under Award Number DMR-1420013. W.Z., J.Z., and X.J.W. appreciate the support from the Legislative-Citizen Commission on Minnesota Resources (LCCMR). The authors thank Dr. Delin Zhang from the Department of Electrical and Computer Engineering at University of Minnesota for transducer deposition and Professor Xu Du from the Department of Physics and Astronomy at Stony Brook University for helping with sample preparation.
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
- Anisotropic optical absorption
- Birefringent optical constants
- Black phosphorus
- Brillouin scattering
- Picosecond interferometry
How much support was provided by MRSEC?
Reporting period for MRSEC
- Period 4
FingerprintDive into the research topics of 'Direct Investigation of the Birefringent Optical Properties of Black Phosphorus with Picosecond Interferometry'. Together they form a unique fingerprint.
11/1/14 → …
Project: Research project