Optoelectronic Properties of Monolayer Hexagonal Boron Nitride on Different Substrates Measured by Terahertz Time-Domain Spectroscopy

Abstract

Monolayer (ML) hexagonal boron nitride (hBN) is an important material in making, e.g., deep ultraviolet optoelectronic and power devices and van der Waals heterojunctions in combination with other two-dimensional (2D) electronic systems such as graphene and ML MoS 2 . In this work, we present a comparative study of the basic optoelectronic properties of low resistance ML hBN placed on different substrates such as SiO 2 /Si, quartz, PET, and sapphire. The measurement is carried out by using terahertz (THz) time-domain spectroscopy (TDS) in a temperature regime from 80 to 280 K. We find that the real and imaginary parts of the optical conductivity obtained experimentally for low resistance ML hBN on different substrates can fit well to the Drude–Smith formula. Thus, we are able to determine optically the key sample and material parameters (e.g., the electronic relaxation time or mobility, the carrier density, the electronic localization factor, etc.) of ML hBN. The effect of temperature on these parameters is also examined and analyzed. The results obtained from this study enable us to suggest the appropriate substrate for ML hBN based electronic and optoelectronic devices. This work is relevant to the application to a newly developed 2D electronic system as advanced electronic and optoelectronic materials.

Magneto‐optical properties of monolayer MoS2‐SiO2/Si structure measured via terahertz time‐domain spectroscopy

“…The details of the THz TDS system used in this study have been documented previously. [ 26,27,35 ] In the experimental setup (see Figure 3), the fs fiber laser is divided into the pump and probe beams. The pump beam is used for generating the THz radiation source and the probe beam is applied, after a time delay, for THz detection.…”

Terahertz magneto-optical properties of graphene hydrodynamic electron liquid

“…In recent years, the THz TDS technique has been employed to investigate into the optoelectronic properties of atomically thin electronic systems such as graphene [23], monolayer (ML) MoS 2 [45], ML WS 2 [46], ML hBN [47], etc. It had been demonstrated experimentally [23] that through MO THz TDS measurement, we can obtained the spectra of the real and imaginary parts FIG.…”

In Situ Measurements of Strain Evolution in Graphene/Boron Nitride Heterostructures Using a Non-Destructive Raman Spectroscopy Approach

“…On the other hand, hexagonal boron nitride (h-BN), an ultra-wide bandgap material, has been shown to possess excellent optical sensitivity, remarkable chemical and thermal stability, and outstanding mechanical properties such as strength. BN has atomically flat surfaces comparable to Gr and a relatively similar lattice structure with a mismatch of only ~1.7% or less [ 9 , 10 , 17 , 18 ]. Additionally, h-BN can possess piezoelectric property under a significant strain (up to 6.2%) owing to the wide bandgap and asymmetric characteristics [ 19 ].…”