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arXiv · 1511.03348

Multilayer black phosphorus as a versatile mid-infrared electro-optic material

Charles Lin·Roberto Grassi·Tony Low·Amr S. Helmy
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Abstract

We investigate the electro-optic properties of black phosphorus (BP) thin films for optical modulation in the mid-infrared frequencies. Our calculation indicates that an applied out-of-plane electric field may lead to red-, blue-, or bidirectional shift in BP's absorption edge. This is due to the interplay between the field-induced quantum-confined Franz-Keldysh effect and the Pauli-blocked Burstein-Moss shift. The relative contribution of the two electro-absorption mechanisms depends on doping range, operating wavelength, and BP film thickness. For proof-of concept, simple modulator configuration with BP overlaid over a silicon nanowire is studied. Simulation result shows that operating BP in the quantum-confined Franz-Keldysh regime can enable improved maximal attainable absorption as well as power efficiency compared to its graphene counterpart.

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Charles Lin, Roberto Grassi, Tony Low, Amr S. Helmy. 2015-11-11. Multilayer black phosphorus as a versatile mid-infrared electro-optic material. https://doi.org/10.1021/acs.nanolett.5b04594

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