Determination of layer-dependent exciton binding energies in few-layer black phosphorus

Abstract

The attraction between electrons and holes in semiconductors forms excitons, which largely determine the optical properties of the hosting material, and hence the device performance, especially for low-dimensional systems. Mono- and few-layer black phosphorus (BP) are emerging two-dimensional (2D) semiconductors. Despite its fundamental importance and technological interest, experimental investigation of exciton physics has been rather limited. Here, we report the first systematic measurement of exciton binding energies in ultrahigh quality few-layer BP by infrared absorption spectroscopy, with layer (L) thickness ranging from 2-6 layers. Our experiments allow us to determine the exciton binding energy, decreasing from 213 meV (2L) to 106 meV (6L). The scaling behavior with layer number can be well described by an analytical model, which takes into account the nonlocal screening effect. Extrapolation to free-standing monolayer yields a large binding energy of ~800 meV. Our study provides insights into 2D excitons and their crossover from 2D to 3D, and demonstrates that few-layer BP is a promising high-quality optoelectronic material for potential infrared applications.

updated version, now 2 layer BP exciton binding energy is included

References in corpus (16)

• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Measurement of the Optical Conductivity of Graphene
• Broadband Linear-Dichroic Photodetector in a Black Phosphorus Vertical p-n Junction
• Tightly bound excitons in monolayer WSe2
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• Waveguide-integrated black phosphorus photodetector with high responsivity and low dark current
• Black Phosphorus Mid-Infrared Photodetectors with High Gain
• Exciton-polariton condensates
• Tunable optical properties of multilayers black phosphorus thin films
• Quasiparticle band structure and tight-binding model for single- and bilayer black phosphorus
• Plasmons and screening in monolayer and multilayer black phosphorus
• Infrared fingerprints of few-layer black phosphorus
• Electrons and holes in phosphorene
• Excitons in anisotropic 2D semiconducting crystals
• Anisotropic exciton Stark shift in black phosphorus
• Theoretical investigation of electron-hole complexes in anisotropic two-dimensional materials

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• Tutorial: Exciton resonances for atomically-thin optics
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• Exciton-Plasmon Coupling in 2D Semiconductors by Surface Acoustic Waves
• Excitons in Phosphorene: A Semi-Analytical Perturbative Approach
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• Non-adiabatic suppression of 3D excitonic screening in black phosphorus by mid-infrared pulses
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