First-Principles Density Functional Theory Study of Modified Germanene-Based Electrode Materials

Abstract

Germanene, with a wrinkled atomic layer structure and high specific surface area, showed high potential as an electrode material for supercapacitors. According to the first-principles calculation based on Density Functional Theory, the quantum capacitance of germanene could be significantly improved by introducing doping/co-doping, vacancy defects and multilayered structures. The quantum capacitance obtained enhancement as a result of the generation of localized states near the Dirac point and/or the movement of the Fermi level induced by doping and/or defects. In addition, it was found that the quantum capacitance enhanced monotonically with the increase of the defect concentration.

Bandgap engineering of germanene for gas sensing applications

“…5m), and 158.6 meV (HSE06 + PBE, Fig. S2m †), which are comparable to that of the previous works, i.e., 80 meV (by GGA-PBE) 68 and 370 meV (by B3LYP), 48 respectively. The isolated vacancy-1 (Fig.…”

Germanium‐based monoelemental and binary two‐dimensional materials: Theoretical and experimental investigations and promising applications

“…The large and adjustable interlamellar spacing of 2D nanosheets can enhance the transmission of ions and electrons and significantly alleviate the volume expansion during the discharge and charge process 11,12,469,470 . The high specific surface area endows them with a large number of effective active sites, thereby accelerating the electrochemical reaction process 147,471–473 . These factors are critical to battery performance and for maintaining the structural integrity.…”

“…11,12,469,470 The high specific surface area endows them with a large number of effective active sites, thereby accelerating the electrochemical reaction process. 147,[471][472][473] These factors are critical to battery performance and for maintaining the structural integrity.…”

Effect of modulation by adsorption and doping on the quantum capacitance of borophene

“…Therefore, it is necessary to improve the C Q of 2D electrode materials. In recent years, researchers have modulated the C Q of two-dimensional materials such as graphene, silicene and germanene by means of defects and doping, [15][16][17] which makes a high density of electron states at the Fermi level.…”