Multilayer Black Phosphorus as a Versatile Mid-Infrared Electro-optic Material

作者：Lin Charles; Grassi Roberto; Low Tony; Helmyt Amr S

来源：Nano Letters, 2016, 16(3): 1683-1689.

DOI：10.1021/acs.nanolett.5b04594

• Black phosphorus
• electro-optics
• quantum-confined Franz-Keldysh effect
• Burstein-Moss shift
• mid-infrared
• modulator

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 results show that operating BP in the quantum-confined Franz-Keldysh regime can improve the maximal attainable absorption as well as power efficiency compared to its graphene counterpart.

• 出版日期2016-3