Exploring Exemplary Optoelectronic and Charge Transport Properties of KCuX(X=Se,Te)

Abstract

We report the electronic structure, optical and charge transport properties of the unexplored ternary Zintl phases KCuX(X=Se,Te) from the first principles calculations employing the full-potential linearized augmented plane-wave (FLAPW) method with the Tran Blaha modified Becke-Johnson (TBmBJ) potential. It is demonstrated that the materials are direct band gap (1.13, 1.38 eV) semiconductors with covalent bonding between Cu and (Se/Te). The calculated low effective mass and high carrier mobility (over 105 cm2/V.s) accentuate that KCuX have good carrier transport and the materials may have possible applications in solar cell absorbers and nanoelectronic devices. Absorption spectra indicates that the ternary crystals are UV-A light absorbers and could be useful in photovoltaic and photodetector applications. A study on the effect of pressure (till 5 GPa) is carried out in order to further explore the materials for their electronic band gaps and charge transport properties as they are proposed to be useful in future contemporary electronic devices. It is observed that pressure enhances the intrinsic carrier mobility and thermal stability of KCuX, indicating that the materials can withstand robust external conditions.

Ultralow lattice thermal conductivity and high thermoelectric performance of monolayer KCuTe: a first principles study

“…Herein, the electronic scattering time τ is 3.5 fs, extracted from previous report. 49 The ZT values with respect to chemical potential and carrier concentration at 300, 500 and 700 K are shown in Fig. 5(a) and (b) .…”

Thermoelectric response of single quintuple layer sodium copper chalcogenides persisting at high temperature

“…22 Bulk KCuX (X = Se, Te) layered semiconductors were predicted to have suitable band gaps for visible light absorption and carrier mobilities as high as 10 5 cm 2 V −1 s −1 . 23 Furthermore, the TE performance of the KCuTe monolayer was anticipated 24 with a κ l value as low as 0.13 W m −1 K −1 at 300 K. Bulk KAgX (X = S, Se, Te) were predicted to possess a low and anisotropic lattice thermal conductivity 25 and single-/few-layered KAgSe nanosheets featured an intrinsically low lattice thermal conductivity and a considerable power factor due to the strong interlayer vibrations and the complete band-extrema alignment. 26,27 Likewise, 2D RbAgSe and TlCuSe semiconductors have very low κ l of 1.01 28 and 0.44 W m −1 K −1 29 at 300 K, respectively.…”

Strain-induced Localization-delocalization Transition on a Lieb Ribbon Lattice

“…And, for germanium kagome lattices 5 a transformation from a semimetallic into a semiconductor is observed when applying compression due to an increment of the orbital frustration that induces an electronic gap. Furthermore, the electronic structure and charge properties were studied in KCuSe and KCuTe 6 , finding that pressure effectively modifies the transport properties due to an enhancement of carrier mobility, which could have direct applications in optoelectronic technologies as, e.g., solar cells.…”