Enhanced nonlinear optical response of graphene-based nanoflake van der Waals heterostructures

• Published in: RSC advances 2021-01, Vol.11 (1), p.559-56
• Main Authors: Kaur, Sumandeep, Pandey, Ravindra, Karna, Shashi P
• Format: Article
• Language: English
• Subjects: Anisotropy; Bilayers; Chemistry; Density functional theory; Electron mobility; Graphene; Heterostructures; Interlayers; Materials selection; Mathematical analysis; Nonlinear optics; Nonlinear response; Nonlinearity; Optical properties; Phosphorene; Second harmonic generation; Two dimensional materials
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d0ra09636a

The nonlinear optical properties of van der Waals bilayer heterostructures composed of graphene/h-BN and graphene/phosphorene nanoflakes are investigated using time-dependent density functional theory. Our calculated results show a significant enhancement of the first-hyperpolarizability value, β in heterostructures relative to the pristine nanoflakes at λ = 1064 nm. The calculated enhancement in optical nonlinearity mainly results from in-plane anisotropy induced by the interlayer electronic coupling between the adjacent nanoflake layers; a higher degree of anisotropy is induced by puckered phosphorene compared to atomically flat h-BN yielding χ (2) value corresponding to the second harmonic generation of ∼50 pm V −1 in the zigzag graphene/phosphorene bilayer heterostructure. The calculated results clearly show that graphene-based nanoflake heterostructures giving large NLO coefficients together with high electron mobility of these materials offer new opportunities as candidate materials of choice for next-generation photonics and integrated quantum technologies. The nonlinear optical properties of van der Waals bilayer heterostructures composed of graphene/h-BN and graphene/phosphorene nanoflakes are investigated using time-dependent density functional theory.