ZnSnN₂ in Real Space and k‐Space: Lattice Constants, Dislocation Density, and Optical Band Gap

Abstract

terms of the earth-abundancy of the material. More specifically, Zn-IV-N 2 with IV = Ge, Sn or Si may have a great potential for optoelectronic applications. Indeed, the direct band gap of Zn-IV-N 2 semiconductors may potentially cover the same range as that of the AlN-GaN-InN alloys, [4] and thus have the potential to be tailored to meet application-specific band gap energies. [1][2][3][5][6][7] In particular, ZnSnN 2 exhibits excellent properties for its use as the solar light absorber in photovoltaics and photocatalysts, but is less explored compared to that of ZnSiN 2 and ZnGeN 2 . According to calculations, the most energetically favorable structure for ZnSnN 2 is the orthorhombic Pna2 1 , although the orthorhombic Pmc2 1 structure has also been identified as a possible structure for ZnSnN 2 .

Li and group-III impurity doping in ZnSnN2 : Potential and limitations

“…series, and independently of [Li]. The carrier mobility varies in the range of 10-30 cm 2 /V s, consistent with the literature data for highly crystalline, undoped samples [24,37]. No correlation between [Li] and n corroborates our, and previously published [7,11,12] theoretical findings, meaning that the Li Zn acceptor is not the dominant configuration.…”

“…[7], a BM shift of 0.2-0.3 eV was calculated for carrier concentrations in the 10 18 -10 21 cm −3 range as typically observed in grown films. Indeed, a band gap in the range of 1.61-1.71 eV is in good agreement with our epitaxially grown ZnSnN 2 [24].…”

“…The main purpose of doping the ZnSnN 2 thin films with Li was to reduce the n-type carrier concentration, n, that for undoped samples remains in the range of 10 20 -10 21 cm −3 for stoichiometric compositions [8,24], as also confirmed in this work. Hall effect measurements at room temperature were conducted to extract n and the carrier mobility, μ, as a function of Li doping (see Fig.…”

“…The ZnSnN 2 thin films were grown on 500-μm-thick single-crystal (0002) ZnO commercial substrates, following the same process as reported in Olsen et al [24]. Prior to the growth, the O-face (000 2) was box implanted with P + ions in order to fabricate a highly resistive surface layer to enable subsequent reliable electrical characterization of the ZnSnN 2 film.…”

“…To ensure that the structural properties of the ZnSnN 2 films remained satisfactorily high [24], as well as to examine any potential phase transformation upon doping, we performed systematic XRD measurements (see Fig. 5 and additional data in the Supplemental Material [34]).…”