Terahertz time-domain spectroscopy (THz-TDS) is a nondestructive imaging and characterization technique. It is currently used in the field of material science to obtain the surface conductivity and transmittance of bulk and 2D materials in the range from hundreds of GHz up to few THz. In this research, an alternative setup of the THz-TDS technique is proposed, based on a Michelson interferometer, with a double pass through the sample using a mirror and a semitransparent wafer. A single-branch configuration is used to characterize a few-layer WS2 sample on a fused quartz substrate. The objectives of the experiment are to demonstrate that the configuration is viable for obtaining the parameters of the sample and the substrate, to present the models and equations used, and to explain the advantages and limitations of the method compared to the transmission configuration. The optical transmittance and surface conductivity of WS2 are obtained with the new configuration in the frequency range from 0.2 to 1.2 THz. Raman spectroscopy is used to analyze the sample quality before performing the measurements.

In this research, it is aimed to obtain and to compare the electrical conductivity and the transmittance of two graphene (Gr)‐based heterostructures: Gr/WS 2 and Gr/MoS 2 on quartz. Raman spectroscopy is used to analyze the quality of the samples before and after the measurements. Terahertz time domain spectroscopy in transmission mode is used as a nondestructive technique to obtain the surface conductivity and the transmittance in the frequency range [0.2, 1.6] THz. The transmittance values obtained for both samples are similar, whereas the surface conductivity of Gr/WS 2 is higher than the one of Gr/MoS 2 and both are higher than the conductivity values obtained for individual homogeneous layers. Fourier transform infrared spectroscopy and UV–Vis spectroscopies are used to obtain the optical transmittance and to evaluate the behavior of each layer in the frequency ranges [90, 180] and [300, 1200] THz, respectively. In the infrared range, the transmittance of the heterostructures is similar to that of the individual materials, although in the visible range the transmittance is totally dominated by the WS 2 and MoS 2 layers. These characteristics make these heterostructures good candidates to be used for optoelectronics sensors.

The electrical conductivity of two‐dimensional (2D) materials without any electrical contact can be obtained using two different methods: the terahertz time domain spectroscopy (THz‐TDS) method, in the range from GHz up to 2 THz, and with a rutile dielectric resonator (RDR), in which case the conductivity is obtained at the resonant frequency of the device, close to 9.0 GHz. In one case (THz‐TDS in a transmission setup), the sample is directly focused. In the other case (RDR), the sample is placed inside the resonant cavity working at mode and must have exactly the same surface size as the cavity, 12 × 12 mm in our device. From the Q factor variation of the resonant cavity due to the sample, its surface resistance is extracted. These measurements are performed on different 2D materials: graphene and . Both methods are analyzed and compared. For few‐layer 2D samples, the THz‐TDS method is suitable.

Measuring the electrical surface resistance of 2D materials without contact can provide a method for obtaining their intrinsic characterization. Herein, the aim is to show that a rutile dielectric resonator (RDR) can be used to measure the electrical surface resistance of conducting coatings deposited on substrates, at the resonance frequency. Moreover, it is known that the substrate exerts a strong influence capable of intrinsically modify the properties of 2D materials, as found in graphene. The RDR method is used for different samples of metals (Cu, Mo, Ti, and brass), carbon nanotubes (bucky paper), a film of compacted graphene flakes, a film of compacted graphene oxide flakes, and graphene obtained by chemical vapor deposition (CVD) on different substrates (SiO2/Si, quartz, and polyethylene terephthalate [PET]). The results show that reasonable values can be obtained for thin conducting materials with a thickness of not less than a few micrometers. In the case of graphene grown on a substrate, the presence of graphene is clearly detected but the resistivity value cannot be extracted.

In the increasing research field of 2D materials such as graphene, molybdenum disulfide MoS2 has attracted great interest due to the existence of a direct bandgap in monolayer MoS2, which gives the possibility of achieving MoS2 field‐effect transistors or optoelectronic devices. We analyzed by THz time‐domain spectroscopy (THz‐TDS) up to 2 THz and infrared (IR) spectroscopy, CVD‐obtained MoS2 using either S or H2S gas as a sulfur precursor, grown on a sapphire substrate. From THz‐TDS we obtained the transmittance, conductivity, and attenuation. From IR spectroscopy on the same samples, we deduced the transmittance in the IR frequency range. We observed the coherence of both spectroscopic methods. The advantage of the THz‐TDS method is that we can get significant parameters related to the sample quality without the need for depositing any electrical contact or sample preparation. Our results show that at high frequencies MoS2 is even better than graphene as a material for optoelectronic devices.