In this study, terahertz (THz) absorption and transmission of monolayer MoS 2 was calculated under different carrier concentrations. Results showed that the THz absorption of monolayer MoS 2 is very small even under high carrier concentrations and large incident angle. Equivalent loss of the THz absorption is the total sum of reflection and absorption that is one to three grades lower than that of graphene.The monolayer MoS 2 transmission is much larger than that of the traditional GaAs and InAs two-dimensional electron gas. The fieldeffect tubular structure formed by the monolayer MoS 2 -insulationlayer-graphene is investigated. In this structure the THz absorption of graphene to reach saturation under low voltage. Meantime, the maximum THz absorption of monolayer MoS 2 was limited to approximately 5%. Thus, monolayer MoS 2 is a kind of ideal THz Transparent Electrodes. 1 Transparent electrode has important prospective applications in the fields of photodetectors, light-emitting diodes (LEDs), vertical cavity surface emitting lasers (VCSELs), and solar cells, et al [1, 2]. As a novel two-dimensional (2-D) material, graphene has high conductivity and very high light transmission within the range of medium infrared and visible light frequency [2-4].Thus, it is regarded as an ideal transparent electrode material. However, the plasmon of graphene exhibits very high terahertz (THz) absorption when the carrier concentration of graphene is high within the THz or far-infrared frequency range [5][6][7][8][9][10][11][12][13][14]. Therefore, graphene with high carrier concentration in THz frequency range is regarded as an absorption medium instead of a transparent electrode.The frequency of the THz range is mainly the spectrum within 0.1-10 THz. Given its special properties, the spectrum of the THz range has broad applications in communication, medical imaging, radar detection, nondestructive tests, and so on [15,16]. The transparent electrode within the THz frequency range has important prospective applications in THz detectors, modulators, VCSELs, and phase shifters [5][6][7][15][16][17][18][19][20][21][22]. Numerous THz transparent electrodes have been suggested, including two-dimensional electron gas (2DEG), ion-gel, two-dimensional arrays of metallic square holes, graphene with low carrier density, and indium-tin-oxide (ITO) nanomaterials. However, Broadband ultra high transmission THz transparent electrodes is still very desirable.Recently, another 2-D material, namely, monolayer MoS 2 , has attracted much research attention. monolayer MoS 2 has high mobility (∼410 cm 2 V −1 s −1 ) and excellent mechanical properties [23][24][25][26][27][28][29][30][31][32][33][34]. However, its optical property is not the same as that of graphene. The monolayer MoS 2 band gap is not zero, which has a high absorption within the visible-light frequency range.This material can be used as a high-efficiency photoelectric detector material instead of an ideal transparent electrode material within the visible light frequency [23-31, 35, 36...