Electronic Structure and Surface Properties of Copper Thiocyanate: A Promising Hole Transport Material for Organic Photovoltaic Cells - data

Considering the significance of hexagonal β-CuSCN in several optoelectronic technologies and applications, it is essential to investigate its electronic structure and surface properties. Herein, we have employed density functional theory (DFT) calculations to characterise the band structure, density of states, and the energy-dependent XPS valence band spectra at variable excitation energies of β-CuSCN. The surface properties in the absence and presence of dimethyl sulfoxide (DMSO), a solvent additive for improving perovskite solar cells' power conversion efficiency, have also been systematically characterized. β-CuSCN is shown to be an indirect band gap material (Eg= 3.68 eV) with the valence band edge is demonstrated to change from being dominated by Cu-3d at soft X-ray ionization photon energies to Cu-3p at hard X-ray ionization photon energies. The adsorption energy of dimethyl sulfoxide (DMSO) on the (100) and (110) β-CuSCN surfaces is calculated at -1.12 and -0.91 eV, respectively. The presence of DMSO on the surface is shown to have a stabilisation effect, lowering the surface energy and tuning the work function of the β-CuSCN surfaces, which is desirable for organic solar cells to achieve high power conversion efficiencies. 

Data underpinning the work are available in the .xlsx format (can be viewed either by MS Office or Libre Office) comprising 6 datasheets named according to their contents.  Data for the optimized CuSCN bulk structure and the DMSO adsorption structures are available in CONTCAR format of the VASP simulation program. The density of states (DOS) data are in 2 columns: the first column been the Energy (eV) and the second column being the intensity of the DOS (arb. units). The band structure data is also in 2 columns: the first column been the K-points and the second column being the Energy (eV).  The data for the energy-dependent XPS valence band spectra of β-CuSCN at variable excitation energies (Al Kα1 (1486 eV), 4068 eV, and 8133 eV) are provided. All data can be plotted using any plotting software, e.g., xmgrace, excel.

Research results based upon these data are published at https://doi.org/10.3390/ma13245765