⇦Chinese Physics Letters, 2020, Vol. 37, No. 9, Article code 097201 Chalcogenide Perovskite YScS$_{3}$ as a Potential p-Type Transparent Conducting Material Han Zhang (张涵)1,2, Chen Ming (明辰)2*, Ke Yang (杨科)3,4, Hao Zeng (曾浩)5, Shengbai Zhang (张绳百)3, and Yi-Yang Sun (孙宜阳)2* Affiliations 1School of Materials Science and Engineering, Shandong University, Jinan 250061, China 2State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China 3Department of Physics, Applied Physics & Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, USA 4School of Physics and Electronics, Hunan University, Changsha 410082, China 5Department of Physics, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA Received 26 August 2020; accepted 27 August 2020; published online 28 August 2020 Y.-Y. Sun was supported by the National Natural Science Foundation of China (Grant No. 11774365). C. Ming was supported by the Natural Science Foundation of Shanghai, China (Grant No. 19ZR1421800) and the Science Foundation for Youth Scholar of State Key Laboratory of High Performance Ceramics and Superfine Microstructures (Grant No. SKL 201804). H. Zeng was supported by the U.S. NSF (Grant Nos. CBET-1510121 and CBET-1510948). K. Yang and S. Zhang were supported by the U.S. DOE (Grant No. DE-SC0002623).
*Corresponding author. Email: mingchen@mail.sic.ac.cn; yysun@mail.sic.ac.cn Citation Text: Zhang H, Ming C, Yang K, Ceng H and Zhang S B et al. 2020 Chin. Phys. Lett. 37 097201    Abstract Transparent conducting materials (TCMs) have been widely used in optoelectronic applications such as touchscreens, flat panel displays and thin film solar cells. These applications of TCMs are currently dominated by n-type doped oxides. High-performance p-type TCMs are still lacking due to their low hole mobility or p-type doping bottleneck, which impedes efficient device design and novel applications such as transparent electronics. Here, based on first-principles calculations, we propose chalcogenide perovskite YScS$_{3}$ as a promising p-type TCM. According to our calculations, its optical absorption onset is above 3 eV, which allows transparency to visible light. Its hole conductivity effective mass is 0.48$m_{0}$, which is among the smallest in p-type TCMs, suggesting enhanced hole mobility. It could be doped to p-type by group-II elements on cation sites, all of which yield shallow acceptors. Combining these properties, YScS$_{3}$ holds great promise to enhancing the performance of p-type TCMs toward their n-type counterparts. DOI:10.1088/0256-307X/37/9/097201 PACS:72.80.Cw, 71.20.Mq, 42.25.Bs, 61.72.uf © 2020 Chinese Physics Society Article Text Introduction. Transparent conducting materials (TCMs) are transparent to visible light and, meanwhile, highly conductive to electrons. By combining the two seemingly incompatible properties, TCMs have found unique applications, e.g., in touchscreens, flat panel displays, and thin film solar cells. Currently, widely used TCMs are exclusively oxides, i.e., In$_{2}$O$_{3}$, SnO$_{2}$, and ZnO.[1–4] These transparent conducting oxides (TCOs) are all n-type doped. The p-type doping of these materials has been notoriously difficult. A main reason is that the valence bands derived from O $2p$ orbitals are too deep to allow shallow acceptors.[5,6] If the performance of p-type TCMs can be on par with their n-type counterparts, not only can the structure design of existing devices be more flexible, but also new transformative applications, such as transparent electronics, could be envisaged.[7–9] This driving force has motivated a vast amount of research developing p-type TCMs.[10–17] Given the success of TCOs, oxides have been first explored for p-type TCMs with CuAlO$_{2}$ and NiO being representative examples.[9,18–20] For these oxides, the p-type doping problem can be solved because the Cu- and Ni-based compounds have relatively high valence band due to the interaction of the $3d$ electrons and O $2p$ valence band.[6] However, the localized O $2p$ orbitals usually result in rather large hole effective masses. As a result, the hole conductivity of oxides is usually on the order of several S$\cdot$cm$^{-1}$,[20] which is to be compared with 10$^{4}$ S$\cdot$cm$^{-1}$ typically achieved by n-type TCOs.[1] For this reason, non-oxide TCMs have been extensively explored.[7] Hole conductivity of two orders of magnitude higher than that of oxides has been achieved by chalcogenides and halides. Currently, the highest reported conductivity in polycrystalline p-type TCMs is 283 S$\cdot$cm$^{-1}$, achieved by CuI.[21,22] Similar high conductivity of 250 S$\cdot$cm$^{-1}$ has also been reported in CuAlS$_{2}$.[23] Given these encouraging works, the search for novel non-oxide high-performance p-type TCMs have been the subject of a number of recent studies.[15–17] Chalcogenide perovskites recently emerge as novel functional materials. Due to the high structure stability, appropriate band gap and good optoelectronic properties, some of these materials have been considered as promising candidates for light-absorbing and light-emitting applications.[24–31] In this Letter, we propose chalcogenide perovskite YScS$_{3}$ for light-transmitting application, as a new p-type TCM. YScS$_{3}$ has been experimentally synthesized half a century ago, but has not been considered as a functional material yet. Here, based on first-principles calculations, we found that (1) its optical absorption onset is above 3 eV allowing transparency to visible light; (2) it has a hole conductivity effective mass of $0.48m_{0}$, which is among the smallest in p-type TCMs; (3) it could be doped to p-type by group-II elements on cation sites, all of which yield shallow acceptors. These properties as the key indicators for an excellent TCM render the perovskite YScS$_{3}$ a promising candidate for p-type TCMs. Computational Method. First-principles calculations in this work were mainly based on density functional theory (DFT). We carried out the calculations using the VASP program.[32] Projector augmented wave (PAW) potentials[33] were used to describe the interaction between ion cores and valence electrons. The wavefunctions were expanded by plane-wave basis sets. Hierarchical exchange-correlation functionals were used in our calculations for different purposes: (1) PBEsol functional[34] being computationally efficient was adopted in molecular dynamics (MD) simulations; (2) strongly constrained and appropriately normed (SCAN) functional[35] was used in calculations on atomic structures and thermodynamic stability of bulk and defects; (3) hybrid HSE functional[36] was used in calculations on band structures, optical absorption, and defect transition levels; (4) PBE functional was used to generate the starting wavefunctions for the $G_{0}W_{0}$ calculations, which produces the quasi-particle band gap.[37] Planewave cutoff energy was taken to be 408 eV whenever cell volume is to be optimized, otherwise, it was taken to be 272 eV. An orthorhombic 2$\times 2\times 2$ supercell of 160 atoms was used in the MD simulations. Another monoclinic 160-atom supercell, generated by a conversion matrix of (2 0 0; 0 1 $-$1; 0 2 2) was used in defect calculations to better separate the dopant atoms. $\varGamma$ point was used in the supercell calculations to represent the Brillouin zone. In bulk calculations, the product of the number of $k$-points and the length of the lattice vector along each direction was greater than 40 Å. In the $G_{0}W_{0}$ calculations, 880 unoccupied bands, a $\varGamma$-centered 6$\times 4\times 6$ $k$-point grid and 380 eV plane-wave cutoff energy were used. The phonon spectra at 0 K was calculated using finite displacement method as implemented in the PHONOPY package.[38] A 2$\times 1\times 2$ supercell was used in second-order force constant calculations. The $k$-point grids for the unit cell and supercell were consistent to ensure high accuracy in force constant calculations. The phonon spectra at elevated temperatures were obtained by the temperature-dependent effective potential (TDEP) method.[39] MD simulations with an NVT ensemble were performed at different temperatures. The simulations were run for 50 ps with a time step of 2 fs. The force constants were extracted from the simulations in the last 40 ps. Results and Discussion. Experimentally, it is reported that YScS$_{3}$ has a crystal structure with $Pna2_{1}$ (No. 33) space group symmetry,[40] which is distorted from the perovskite structure with $Pnma$ (No. 62) space group by slightly displacing the Sc atom away from the octahedron center. The determination of space group, however, could be subject to uncertainty. For example, the space group of CeScS$_{3}$ was redetermined after the initial study[41] and reported to be $Pnma$.[42,43] In this work, we started from the experimental structure and carried out relaxations using PBEsol, SCAN, and HSE functionals. All methods ended up with the $Pnma$ symmetry.
cpl-37-9-097201-fig1.png
Fig. 1. (a) Relative energy of YScS$_{3}$ in 23 octahedron rotation patterns following Glazer's notation with respect to the lowest energy pattern. (b) Enthalpy of formation of YScS$_{3}$ in five different structures. (c) Atomic structure of YScS$_{3}$ in the GdFeO$_{3}$ (i.e., perovskite) structure in two different views. (d) Atomic structure of YScS$_{3}$ in the UFeS$_{3}$ (or post-perovskite) structure in two different views.
We also carried out a systematic determination of the particular octahedron rotation pattern in the perovskite structure by employing Glazer's notation,[44] which classified the octahedron rotation into 23 possibilities. In these calculations, we employed a supercell containing 8 octahedra (i.e., a 2$\times 2\times 2$ supercell based on the non-distorted cubic perovskite unit cell) to accommodate the alternating octahedron rotations between nearest neighbors. PBEsol functional was used in these calculations. Figure 1(a) shows the calculated total energy with respect to the most stable rotation pattern. After relaxation, the patterns from 8 to 11 all yielded the $Pnma$ structure, which is the lowest energy configuration. Based on the results above, we consider that YScS$_{3}$ is in the $Pnma$ perovskite structure in this work.
cpl-37-9-097201-fig2.png
Fig. 2. The phonon spectra of YScS$_{3}$ in the perovskite structure at various temperatures. The TDEP method was used to extract the phonon spectra from MD simulations at corresponding temperatures.
We next compared the $Pnma$ perovskite structure (or GdFeO$_{3}$ structure) with other possible structures that could be adopted by the $AB$S$_{3}$ compounds. Figure 1(b) shows the calculated enthalpy of formation of YScS$_{3}$ in different structures with respect to binary sulfides, Y$_{2}$S$_{3}$ and Sc$_{2}$S$_{3}$, which are in structures with space groups of $Pnma$ and $Fddd$ (No. 70), respectively. The SCAN functional was used to optimize the structure and calculate the total energies. We first considered the NH$_{4}$CdCl$_{3}$ structure, which is the structure of a number of $AB$S$_{3}$ compounds, such as BaSnS$_{3}$[45] and SrZrS$_{3}$.[46] Another structure with hexagonal lattice and space group $P6_{3}$/$mmc$ (No. 194), as adopted by BaTiS$_{3}$,[47] has rather high energy (about 2.6 eV higher than the perovskite structure) and is not shown in Fig. 1(b). The next important structure in Fig. 1(b) is the UFeS$_{3}$ structure,[48] which is also called post-perovskite structure in the literature.[49] According to our calculation, YScS$_{3}$ in this structure is slightly more stable than the perovskite structure. However, the energy difference is only 17 meV per formula unit (f.u.) of YScS$_{3}$. Given the fact that YScS$_{3}$ experimentally exists in the perovskite structure, this small energy difference is considered to be either the uncertainty in the calculation method or the possibility of another phase of YScS$_{3}$ to be discovered experimentally. The optimized lattice constants and atomic coordinates of this structure are given in the Supplementary Material. Another two considered structures are the CuTaS$_{3}$[50] and CeTmS$_{3}$[51] structures. The latter structure is also adopted by LaYS$_{3}$, which was recently proposed for photocatalytic applications.[52] Our results show that these two structures are not competitive to the perovskite structure. Figures 1(c) and 1(d) show the atomic structures of YScS$_{3}$ in the perovskite and UFeS$_{3}$ structures, respectively, which will be discussed below in more details. To further check the stability of YScS$_{3}$ in the perovskite structure at high temperatures, we carried out MD simulations and extracted phonon spectra from the MD trajectories, as shown in Fig. 2. No imaginary modes are observed in the spectra from 0 K up to 1500 K, suggesting its kinetic stability. When the temperature is increased, the high-frequency optical modes become softened, i.e., their frequencies decrease. In contrast, the low-frequency optical modes, especially the lowest mode at the $\varGamma$ point, are hardened. Usually, the soft modes close to zero indicate the direction of phase change or kinetic instability. The hardening of soft modes suggests that increased temperature helps stabilize the perovskite structure. After evaluating the stability of YScS$_{3}$ in the perovskite structure, we next study its optoelectronic properties. Figure 3(a) shows the band structure of perovskite YScS$_{3}$, which has an indirect gap with the valence band maximum (VBM) at the $\varGamma$ point and the conduction band minimum (CBM) at the $Y$ point. The indirect gap from HSE calculation is 2.79 eV, while the direct gap at the $\varGamma$ point is 2.98 eV. Figure 3(b) shows the partial charge density plots for the VBM state at the $\varGamma$ point (bottom panel) and the CBM state at the $Y$ point (middle panel). Also shown is the lowest unoccupied state at the $\varGamma$ point (top panel), referred to as CBM-$\varGamma$ state. It can be seen that the VBM state is predominantly composed of S $3p$ orbitals, while the CBM-$\varGamma$ state is predominantly composed of Sc $3d$ orbitals. Not unexpected, the CBM state is a hybridized state between the Y $4d$ and Sc $3d$ orbitals. The lower energy of the CBM state than the CBM-$\varGamma$ state is possibly a result of the stronger coupling between the Y $4d$ and Sc $3d$ orbitals at the $Y$ point. To further confirm the predicted band gap, we used the quasi-particle $G_{0}W_{0}$ calculation. The indirect gap from $\varGamma$ to $Y$ is found to increase to 3.16 eV and the direct gap at the $\varGamma$ point is increased to 3.46 eV. It is expected that the actual band gap of perovskite YScS$_{3}$ is located between the HSE and $G_{0}W_{0}$ results. Figure 3(c) shows the band structure of YScS$_{3}$ in the UFeS$_{3}$ structure. Here, the direct gap at the $\varGamma$ point is 2.12 eV and the indirect gap between the VBM at the $\varGamma$ point and the CBM at the $Y$ point is 1.30 eV. Both values are significantly smaller than that in the perovskite structure. In the UFeS$_{3}$ structure, the VBM state is still contributed by S $3p$ orbitals. Different from the case in the perovskite structure, however, the CBM and CBM-$\varGamma$ states are contributed by Y $4d$ and Sc $3d$ orbitals exclusively. It is worth noting that the isosurface values in the plots in Figs. 3(b) and 3(d) depend on the states. For the CBM states, the value is 0.005 electron/Å$^{3}$, while for the VBM and CBM-$\varGamma$ states, the value is set to be 50 times smaller, suggesting that the CBM states are much more delocalized.
cpl-37-9-097201-fig3.png
Fig. 3. (a) Band structure of YScS$_{3}$ in the perovskite structure obtained using HSE calculation. Inset shows the Brillouin zone and the high-symmetry $k$ points. (b) Partial charge density plots of VBM and CBM states, as well as the CBM state at the $\varGamma$ point. (c) and (d) are similar to (a) and (b), but for YScS$_{3}$ in the UFeS$_{3}$ structure.
cpl-37-9-097201-fig4.png
Fig. 4. (a) Parabolic fitting of the top valence band of perovskite YScS$_{3}$ along $\varGamma$–$X$, $\varGamma$–$Y$, and $\varGamma$–$Z$ directions to obtain the effective masses of holes along the three directions. The data points were obtained using HSE $+$ SOC calculation. The unit of effective masses is $m_{0}$, the mass of an electron. (b) Imaginary part of dielectric constant ($\varepsilon_{2}$) of perovskite YScS$_{3}$ along the three directions obtained using HSE calculation.
The figure of merit of a TCM can be expressed as the ratio of electrical conductivity to optical absorption coefficient for visible light. As a p-type TCM, the electrical conductivity is intrinsically determined by the effective mass of holes and, in addition, by a variety of carrier scattering mechanisms. We calculated the hole effective masses by a parabolic fitting to the top valence band using the HSE functional plus SOC effect (HSE $+$ SOC). The results are shown in Fig. 4(a). The top valence band near the $\varGamma$ point shows anisotropy. The $\varGamma$–$Y$ direction exhibits more prominent band dispersion with an effective mass of $0.22m_{0}$. The $\varGamma$–$X$ and $\varGamma$–$Z$ directions have an effective mass of $1.41m_{0}$ and $0.98m_{0}$, respectively. The conductivity effective mass of holes according to[53] $$ m_{\rm c}=3\left( \frac{1}{m_{\rm h}^{1}}+\frac{1}{m_{\rm h}^{2}}+\frac{1}{m_{\rm h}^{3}} \right)^{-1}~~ \tag {1} $$ is calculated to be $0.48m_{0}$, which is an attractive value for p-type materials. As a comparison, we calculated the $m_{\rm c}$ of holes for CuAlS$_{2}$, which has been demonstrated to exhibit the highest conductivity (250 S$\cdot$cm$^{-1}$) among chalcogenide p-type TCMs. CuAlS$_{2}$ has a tetragonal structure. Our HSE $+$ SOC calculation yielded $m_{\rm h}^{x}=m_{\rm h}^{y}=1.14 m_{0}$ and $m_{\rm h}^{z}=0.40 m_{0}$, giving rise to $m_{\rm c}=0.71 m_{0}$. Currently, the highest conductivity of polycrystalline p-type TCMs (283 S$\cdot$cm$^{-1}$) is held by the halide CuI, which is in zinc-blende structure. According to our HSE $+$ SOC calculation, its hole effective masses along the $\varGamma$–$L$, $\varGamma$–$X$, and $\varGamma$–$K$ directions are $1.72m_{0}$, $0.60m_{0}$, and $1.24m_{0}$, respectively, giving rise to $m_{\rm c}=0.98 m_{0}$. A longer list of effective masses of p-type TCMs as collected from a computational electronic transport database[54] is given in the Supplementary Material. The comparison suggests that perovskite YScS$_{3}$ having the smallest conductivity effective mass could improve the conductivity of p-type TCMs toward their n-type counterparts. The optical absorption coefficient is determined by the imaginary part of the dielectric constant ($\varepsilon_{2}$). For TCMs, it is required that the absorption onset is above 3 eV so that the visible light can be efficiently transmitted. Figure 4(b) shows the calculated $\varepsilon_{2}$ of perovskite YScS$_{3}$. The anisotropy here is weaker than that for effective masses as shown in Fig. 4(a). The three diagonal elements of $\varepsilon_{2}$ (i.e., $\varepsilon_{2}^{xx}$, $\varepsilon_{2}^{yy}$, and $\varepsilon_{2}^{zz}$) all exhibit weak absorption below 3 eV and sharp increase above that, ensuring perovskite YScS$_{3}$ to be a promising TCM. We also calculated the $\varepsilon_{2}$ of YScS$_{3}$ in the UFeS$_{3}$ structure, as shown in the Supplementary Material. Even though the indirect gap of YScS$_{3}$ in this structure is only 1.3 eV, its optical absorption onset is around 2.3 eV and the sharp increase occurs above 3 eV. It is expected that this phase will absorb a small portion of visible light in the green to violet region. The conductivity is also determined by the carrier concentration, which in turn depends on the doping efficiency. For wide gap semiconductors like TCMs, the doping bottleneck is often a challenging issue. The widely used TCO materials all suffer from the difficulty of p-type doping.[5,6] Here, for YScS$_{3}$ we considered group-II element (Mg, Ca, Sr, Ba, and Zn) doping on the Y and Sc sites. The defect transition level between two charge states $q$ and $q'$ was determined by $$ \epsilon \left( q / q' \right)=\left( E_{\rm D}^{q}-E_{\rm D}^{q'} \right) \Big/ \left( q'-q \right)-E_{\mathrm{VBM}},~~ \tag {2} $$ where $E_{\rm D}^{q}$ and $E_{\rm D}^{q'}$ are the total energies of the defect supercell in the $q$ and $q'$ charge states and $E_{\mathrm{VBM}}$ is the Kohn–Sham eigenvalue of the VBM state. Our results obtained using the SCAN functional show that group-II elements on both Y and Sc sites are all shallow acceptors with $\epsilon \left( 0/- \right)$ smaller than 0.01 eV above the VBM. The formation energies from the SCAN functional, as listed in the Supplementary Material, suggest that Mg prefers to be on the Sc sites, Ca, Sr, and Ba prefer to be on the Y sites, while Zn shows similar formation energy on the two sites. Sr-on-Y (Sr$_{\rm Y}$) doping is energetically the most favored. We further calculated the formation energy of Sr$_{\rm Y}$ and S vacancy ($V_{\rm S}$) as a function of Fermi level ($E_{\rm F}$) using the HSE functional. The p-type YScS$_{3}$ requires to be prepared under S-rich conditions to avoid the compensation due to intrinsic donor defects, especially, $V_{\rm S}$. Figure 5 is obtained using the S-rich condition. It can be seen that under the S-rich condition, the $V_{\rm S}$ defect has rather high formation energy. According to Fig. 5, the lowest formation energy of $V_{\rm S}$ is 1.03 eV at the VBM, while the formation energy of Sr$_{\rm Y}$ is only slightly higher than $V_{\rm S}$ by 0.15 eV, which results in the pinned $E_{\rm F}$ at 0.05 eV above the VBM, suggesting a good p-type semiconductor by Sr doping. It is noted that $V_{\rm S}$ is a deep donor according to our HSE calculation. The inset of Fig. 5 shows the partial charge density of $V_{\rm S}$ corresponding to the Kohn–Sham state in the band gap, which is rather localized. For the charged localized defects, it is necessary to consider the interaction between the periodic images of the localized charge. For this purpose, we considered the Madelung correction, which could overestimate the image-charge interaction, but the error is usually small for image distance above 15 Å.[55] The correction for $+$2 and $+$1 states of $V_{\rm S}$ is 0.85 and 0.21 eV, respectively, using dielectric constant of 6.37 obtained from the optical absorption calculation above.
cpl-37-9-097201-fig5.png
Fig. 5. Formation energy of Sr-on-Y (Sr$_{\rm Y}$) p-type dopant and the intrinsic S vacancy ($V_{\rm S}$) defect as a function of Fermi level ($E_{\rm F}$), which is measured between the VBM and CBM calculated by HSE functional from the 160-atom supercell. The dots mark the transition energy between two charge states. The inset shows the partial charge density of the $V_{\rm S}$ defect state.
Conclusions. We propose that YScS$_{3}$ in the perovskite structure could be an excellent p-type TCM. To support this proposal, we carried out first-principles calculations on four aspects of the properties of YScS$_{3}$: stability, transparency, mobility, and doping. (1) Even though the perovskite is the only experimentally reported phase, there might exist a competing phase in the UFeS$_{3}$ structure, which is worth attention in future experiments. According to our calculated phonon spectra up to 1500 K, no sign of kinetic instability was observed in the perovskite YScS$_{3}$. (2) The optical absorption onset is predicted to be about 3 eV by hybrid HSE functional. $G_{0}W_{0}$ calculation suggests even higher onset by about 0.5 eV, ensuring full transmission of visible light. (3) The calculated conductivity effective mass of holes is $0.48m_{0}$, which is among the smallest in materials with the optical absorption onset above 3 eV. (4) The p-type doping could be achieved by group-II elements on the cation sites, all of which could produce shallow acceptors. With the predicted properties, it is expected that the performance of p-type TCMs could be improved over the current state of the art towards that of n-type TCMs. References Past achievements and future challenges in the development of optically transparent electrodesTransparent Electrodes for Efficient OptoelectronicsTransparent conducting oxides for electrode applications in light emitting and absorbing devicesTransparent conducting oxide films for thin film silicon photovoltaicsThe microscopic origin of the doping limits in semiconductors and wide-gap materials and recent developments in overcoming these limits: a reviewOvercoming the doping bottleneck in semiconductorsWide Band Gap Chalcogenide SemiconductorsTransparent conducting materials discovery using high-throughput computingP -type transparent conducting oxidesIdentification and design principles of low hole effective mass p-type transparent conducting oxidesHigh-Mobility Bismuth-based Transparent p -Type Oxide from High-Throughput Material ScreeningAssessing High-Throughput Descriptors for Prediction of Transparent ConductorsLarge-Scale Computational Identification of p-Type Oxide Semiconductors by Hierarchical ScreeningHigh-Throughput Design of Non-oxide p-Type Transparent Conducting Materials: Data Mining, Search Strategy, and Identification of Boron PhosphideMachine Learning Optimization of p-Type Transparent Conducting FilmsRational design of transparent p-type conducting non-oxide materials from high-throughput calculationsP-type electrical conduction in transparent thin films of CuAlO2Transparent conducting p-type NiO thin films prepared by magnetron sputteringRecent Developments in p-Type Oxide Semiconductor Materials and DevicesRoom-temperature synthesized copper iodide thin film as degenerate p-type transparent conductor with a boosted figure of meritTruly Transparent p-Type γ-CuI Thin Films with High Hole MobilityHighly enhanced p-type electrical conduction in wide band gap Cu1+xAl1−xS2 polycrystalsChalcogenide Perovskites for PhotovoltaicsChalcogenide perovskites – an emerging class of ionic semiconductorsStability and Band-Gap Tuning of the Chalcogenide Perovskite BaZrS 3 in Raman and Optical Investigations at High PressuresThermal stability study of transition metal perovskite sulfidesRealization of BaZrS3 chalcogenide perovskite thin films for optoelectronicsBandgap Control via Structural and Chemical Tuning of Transition Metal Perovskite ChalcogenidesAlloying and Defect Control within Chalcogenide Perovskites for Optimized Photovoltaic ApplicationMaterial Design of Green-Light-Emitting Semiconductors: Perovskite-Type Sulfide SrHfS 3Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis setFrom ultrasoft pseudopotentials to the projector augmented-wave methodRestoring the Density-Gradient Expansion for Exchange in Solids and SurfacesStrongly Constrained and Appropriately Normed Semilocal Density FunctionalHybrid functionals based on a screened Coulomb potentialElectron correlation in semiconductors and insulators: Band gaps and quasiparticle energiesFirst principles phonon calculations in materials scienceLattice dynamics of anharmonic solids from first principlesCerium scandium sulphide: structure refinement by powder neutron diffractionCrystal structure of cerium scandium trisulfide, CeScS3The classification of tilted octahedra in perovskitesPreparations of BaSnS3, SrSnS3 and PbSnS3 at high pressureSynthesis, structure, and electronic and physical properties of the two SrZrS3 modificationsUntersuchungen �ber tern�re Chalkogenide. XI. Versuche zur Darstellung von ThioperowskitenStructure cristalline de FeUS 3Post-Perovskite Phase Transition in MgSiO3Structure cristalline du sulfure mixte de thulium et de cérium TmCeS3Sulfide perovskites for solar energy conversion applications: computational screening and synthesis of the selected compound LaYS 3An ab initio electronic transport database for inorganic materialsFully Ab Initio Finite-Size Corrections for Charged-Defect Supercell Calculations
[1] Ellmer K 2012 Nat. Photon. 6 809
[2] Morales-Masis M, De Wolf S, Woods-Robinson R, Ager J W and Ballif C 2017 Adv. Electron. Mater. 3 1600529
[3] Liu H, Avrutin V, Izyumskaya N, Özgür Ü and Morkoç H 2010 Superlattices Microstruct. 48 458
[4] Beyer W, Hüpkes J and Stiebig H 2007 Thin Solid Films 516 147
[5] Zhang S B 2002 J. Phys.: Condens. Matter 14 R881
[6] Wei S H 2004 Comput. Mater. Sci. 30 337
[7] Woods-Robinson R, Han Y, Zhang H, Ablekim T, Khan I, Persson K A and Zakutayev A 2020 Chem. Rev. 120 4007
[8] Brunin G, Ricci F, Ha V A, Rignanese G M and Hautier G 2019 npj Comput. Mater. 5 63
[9] Zhang K H L, Xi K, Blamire M G and Egdell R G 2016 J. Phys.: Condens. Matter 28 383002
[10] Hautier G, Miglio A, Ceder G, Rignanese G M and Gonze X 2013 Nat. Commun. 4 2292
[11] Bhatia A, Hautier G, Nilgianskul T, Miglio A, Sun J, Kim H J, Kim K H, Chen S, Rignanese G M, Gonze X and Suntivich J 2016 Chem. Mater. 28 30
[12]Williamson B A, Buckeridge J, Brown J, Ansbro S, Palgrave R G and Scanlon D O 2016 Chemistry of Materials acs.chemmater.6b03306
[13] Woods-Robinson R, Broberg D, Faghaninia A, Jain A, Dwaraknath S S and Persson K A 2018 Chem. Mater. 30 8375
[14] Youn Y, Lee M, Kim D, Jeong J K, Kang Y and Han S 2019 Chem. Mater. 31 5475
[15] Varley J B, Miglio A, Ha V A, van Setten M J, Rignanese G M and Hautier G 2017 Chem. Mater. 29 2568
[16] Wei L, Xu X, Gurudayal, Bullock J and Ager J W 2019 Chem. Mater. 31 7340
[17] Kormath Madam Raghupathy R, Kühne T D, Felser C and Mirhosseini H 2018 J. Mater. Chem. C 6 541
[18] Kawazoe H, Yasukawa M, Hyodo H, Kurita M, Yanagi H and Hosono H 1997 Nature 389 939
[19] Sato H, Minami T, Takata S and Yamada T 1993 Thin Solid Films 236 27
[20] Wang Z, Nayak P K, Caraveo-Frescas J A and Alshareef H N 2016 Adv. Mater. 28 3831
[21] Yang C, Knei M, Lorenz M and Grundmann M 2016 Proc. Natl. Acad. Sci. USA 113 12929
[22] Yamada N, Ino R and Ninomiya Y 2016 Chem. Mater. 28 4971
[23] Huang F Q, Liu M L and Yang C 2011 Sol. Energy Mater. Sol. Cells 95 2924
[24] Sun Y Y, Agiorgousis M L, Zhang P and Zhang S 2015 Nano Lett. 15 581
[25] Perera S, Hui H, Zhao C, Xue H, Sun F, Deng C, Gross N, Milleville C, Xu X, Watson D F, Weinstein B, Sun Y Y, Zhang S and Zeng H 2016 Nano Energy 22 129
[26] Gross N, Sun Y Y, Perera S, Hui H, Wei X, Zhang S, Zeng H and Weinstein B A 2017 Phys. Rev. Appl. 8 044014
[27] Niu S, Milam-Guerrero J, Zhou Y, Ye K, Zhao B, Melot B C and Ravichandran J 2018 J. Mater. Res. 33 4135
[28] Wei X, Hui H, Zhao C, Deng C, Han M, Yu Z, Sheng A, Roy P, Chen A, Lin J, Watson D F, Sun Y Y, Thomay T, Yang S, Jia Q, Zhang S and Zeng H 2020 Nano Energy 68 104317
[29] Niu S, Huyan H, Liu Y, Yeung M, Ye K, Blankemeier L, Orvis T, Sarkar D, Singh D J, Kapadia R and Ravichandran J 2017 Adv. Mater. 29 1604733
[30] Meng W, Saparov B, Hong F, Wang J, Mitzi D B and Yan Y 2016 Chem. Mater. 28 821
[31] Hanzawa K, Iimura S, Hiramatsu H and Hosono H 2019 J. Am. Chem. Soc. 141 5343
[32] Kresse G and Furthmüller J 1996 Comput. Mater. Sci. 6 15
[33] Kresse G and Joubert D 1999 Phys. Rev. B 59 1758
[34] Perdew J P, Ruzsinszky A, Csonka G I, Vydrov O A, Scuseria G E, Constantin L A, Zhou X and Burke K 2008 Phys. Rev. Lett. 100 136406
[35] Sun J, Ruzsinszky A and Perdew J P 2015 Phys. Rev. Lett. 115 036402
[36] Heyd J, Scuseria G E and Ernzerhof M 2003 J. Chem. Phys. 118 8207
[37] Hybertsen M S and Louie S G 1986 Phys. Rev. B 34 5390
[38] Togo A and Tanaka I 2015 Scr. Mater. 108 1
[39] Hellman O, Abrikosov I A and Simak S I 2011 Phys. Rev. B 84 180301
[40]Rodier N and Laruelle P 1970 C. R. Acad. Sc. (Paris) C270 2127
[41]Rodier N, Laruelle P and Flahaut J 1969 C. R. Acad. Sc. (Paris) C269 1391
[42] IJdo D 1980 Acta Crystallogr. Sect. B 36 2403
[43] Range K J, Gietl A and Klement U 1993 Z. Kristallogr. 207 147
[44] Glazer A 1972 Acta Crystallogr. Sect. B 28 3384
[45] Yamaoka S and Okai B 1970 Mater. Res. Bull. 5 789
[46] Lee C S, Kleinke K M and Kleinke H 2005 Solid State Sci. 7 1049
[47] Hahn H and Mutschke U 1957 Z. Anorg. Allg. Chem. 288 269
[48] Noel H and Padiou J 1976 Acta Crystallogr. Sect. B 32 1593
[49] Murakami M, Hirose K, Kawamura K, Sata N and Ohishi Y 2004 Science 304 855
[50]Crevecoeur C and Romers C 1964 Proc. Koninklijke Nederlandse Acad. Van Wetenschappen 67 289
[51] Rodier N 1973 Bull. La Societe Francaise Mineralogie Cristallographie 96 350
[52] Kuhar K, Crovetto A, Pandey M, Thygesen K S, Seger B, Vesborg P C K, Hansen O, Chorkendorff I and Jacobsen K W 2017 Energy & Environ. Sci. 10 2579
[53]Sze S M 1969 Physics of Semiconductor Devices (New Jersey: Wiley)
[54] Ricci F, Chen W, Aydemir U, Snyder G J, Rignanese G M, Jain A and Hautier G 2017 Sci. Data 4 170085
[55] Freysoldt C, Neugebauer J and van de Walle C G 2009 Phys. Rev. Lett. 102 016402