---

Electronic structure [Reference]

The following shows the electronic density of states and bandstructure [Source-code]. DFT is generally predicted to underestimate bandgap of materials. Accurate band-gaps are obtained with higher level methods (with high computational requirement) such as HSE, GW , which are under progress. If available, MBJ data should be comparable to experiments also. Total DOS, Orbital DOS and Element dos [Source-code] buttons are provided for density of states options. Energy is rescaled to make Fermi-energy zero. In the bandstructure plot [Source-code], spin up is shown with blue lines while spin down are shown with red lines. Non-degenerate spin-up and spin-down states (if applicable) would imply a net orbital magnetic moment in the system. Fermi-occupation tolerance for bandgap calculation is chosen as 0.001.

High-symmetry kpoints based bandgap (eV): 1.755I

Total DOS Orbital DOS Element DOS

---

Electrostatic potential [Reference]

The following plot shows the plane averaged electrostatic potential (ionic+Hartree) along x, y and z-directions. The red line shows the Fermi-energy while the green line shows the maximum value of the electrostatic potential. For slab structures (with vacuum along z-direction), the difference in these two values can be used to calculate work-function of the material.

---

Optoelectronic properties Semi-local [Reference]

Incident photon energy dependence of optical is shown below [Source-code]. Only interband optical transitions are taken into account.Please note the underestimatation of band-gap problem with DFT will reflect in the spectra as well. For very accurate optical properties GW/BSE calculation would be needed, which is yet to be done because of their very high computational cost. Optical properties for mono-/multi-layer materials were rescaled with the actual thickness to simulation z-box ratio. Absorption coeffiecient is in cm-1 unit. Also, ionic contributions were neglected.

Dense k-mesh based bandgap is : 1.7803 eV

Static real-parts of dielectric function in x,y,z: 8.64,8.64,8.2

---

Optoelectronic properties METAGGA-MBJ [Reference]

Single point DFT calculation was carried out with meta-gga MBJ potential [Source-code]. This should give reasonable bandgap, and optical properties assuming the calculation was properly converged. Incident photon energy dependence of optical is shown below. Only interband optical transitions are taken into account. Also, ionic contributions were neglected.

MBJ bandgap is : 2.3767 eV

Static real-parts of dielectric function in x,y,z: 7.54,7.54,7.17

---

Solar-cell SLME [Reference]

Theoretical solar-cell efficiency (in %) was calculated using spectroscopy limited maximum efficiency (SLME) and TBmBJ for the material with 500 nm thickness and at 300 K. Note that generally there are many factors that contribute towards the efficiency, such as carrier effective mass etc.

SLME is: 15.0

---

DFPT: IR-intensity, Piezoelecric and Dielectric tensors [Reference]

Calculations are done using density functional perturbation theory (DFPT) method for non-metallic systems for conventional cell and at Gamma-point in phonon BZ.

Static dielecric-tensor

14.97	0.0	-0.0
-0.0	14.97	-0.0
-0.0	-0.0	17.82

Piezoelectric-stress-tensor (C/m²)

0.0	0.0	0.0	0.0	0.06	0.22
0.0	-0.0	-0.0	0.0	0.22	-0.06
0.44	0.44	-1.2	0.0	0.0	0.0

---

Thermoelectric properties [Reference]

Thermoelectric properties are calculated using BoltzTrap code [Source-code]. Electron and hole mass tensors (useful for semiconductors and insulators mainly)are given at 300 K [Source-code]. Following plots show the Seebeck coefficient and ZT factor (eigenvalues of the tensor shown) at 300 K along three different crystallographic directions. Seebeck coefficient and ZT plots can be compared for three different temperatures available through the buttons given below. Generally very high Kpoints are needed for obtaining thermoelectric properties. We assume the Kpoints obtained from above convergence were sufficient [Source-code].

WARNING: Constant relaxation time approximation (10^-14 s) and only electronic contribution to thermal conductivity were utilized for calculating ZT.

Electron mass tensor (m_e unit)

Hole mass tensor (m_e unit)