Impurity Doping in Mg(OH)2 for n-Type and p-Type Conductivity Control

Abstract

<jats:p>Magnesium hydroxide (Mg(OH)2) has a wide bandgap of about 5.7 eV and is usually considered an insulator. In this study, the energy levels of impurities introduced into Mg(OH)2 are predicted by first-principles calculations. A supercell of brucite Mg(OH)2 consisting of 135 atoms is used for the calculations, and an impurity atom is introduced either at the substitutional site replacing Mg or the interlayer site. The characteristics of impurity levels are predicted from density-of-states analysis for the charge-neutral cell. According to the results, possible shallow donors are trivalent cations at the substitutional site (e.g., Al and Fe) and cation atoms at the interlayer site (Cu, Ag, Na, and K). On the other hand, an interlayer F atom can be a shallow acceptor. Thus, valence control by impurity doping can turn Mg(OH)2 into a wide-gap semiconductor useful for electronics applications.</jats:p>

Fabrication of Transparent Mg(OH)2 Thin Films by Drop-Dry Deposition

“…The origin of the conductivity of the Mg(OH)2 films is not understood. According to the firstprinciples calculation, both native defects and impurities can donate carriers in Mg(OH)2 [8]. Possible impurities are Na + from NaOH and NO3 -from Mg(NO3)2.…”

“…The constituent element Mg is an abundant substance with the eighth largest Clarke number. Impurity doping in Mg(OH) 2 was investigated by first-principles calculation, and it was predicted that Mg(OH) 2 can have both n and p-type conductivity by proper impurity doping [8]. Several research groups actually fabricated solar cells with a Mg(OH) 2 layer inserted to enhance output voltage [9][10][11].…”

A comprehensive study on the electronic structure, dielectric and optical properties of alkali‐earth metals and transition metal hydroxides M(OH)2

“…However, these can turn into wide band gap semiconductors by introducing doping effects, which may be helpful for application in electronic devices. [ 30 ] Zn(OH) 2 exhibits high carrier mobility comparable ZnO. Hence, it can be thought of as a substitute for ZnO in electronic devices.…”

Engineering Electronic Structure and Band Alignment of 2D Mg(OH)2 via Anion Doping for Photocatalytic Applications

“…Cobalt doping is examined to tune the bandgap of Mg(OH) 2 , and 10% Co-doping slightly narrows the band gap from 5.47 eV of pure Mg(OH) 2 to 5.26 eV [ 19 ]. Doping of Na, K, Cu, Ag, F, Cl, and C at interlayer sites, and K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Al, Si, Sn, and C at substitutional sites were evaluated to give Mg(OH) 2 n-type or p-type conductivity [ 27 ]. However, remarkable bandgap variation was not observed.…”

“…It is encouraging to notice that the heavily C-doped Mg(OH) 2 films are electrically conducting [ 28 , 29 ]. It is initially speculated that C atoms replace H and bond to O [ 20 ], but isolated C atoms cannot induce significant conduction [ 27 ]. C atoms of large content are supposed to form a 2D graphite-like structure in Mg(OH) 2 to render it metallic conductive.…”