Copper thiocyanate: polytypes, defects, impurities, and surfaces.

Area of Science:

• Materials Science
• Solid-State Physics
• Computational Chemistry

Background:

• Copper thiocyanate (CuSCN) is a significant material in solar cells, transparent conductors, and thin-film transistors.
• Understanding its fundamental properties is crucial for optimizing its performance in these applications.

Purpose of the Study:

• To investigate the structural, electronic, and defect properties of copper thiocyanate (CuSCN) using density-functional theory (DFT).
• To explore the impact of polytypism, defects, and hydrogen impurities on CuSCN's electronic characteristics.
• To assess the surface properties of CuSCN for potential fabrication advantages.

Main Methods:

• Density-functional theory (DFT) calculations were employed.
• Structural and electronic properties of various CuSCN phases were analyzed.
• The effects of defects and hydrogen impurities on electronic properties were systematically studied.
• Surface formation energies were calculated.

Main Results:

• CuSCN exhibits polytypism, with different structural phases identified.
• Defects and hydrogen impurities significantly influence the electronic properties, impacting doping behavior.
• Non-polar surfaces of CuSCN possess low formation energies.
• The material shows a propensity for cleavage along specific directions.

Conclusions:

• CuSCN's polytypism and sensitivity to defects/impurities are key factors for its electronic behavior.
• Low surface formation energies suggest facile processing and fabrication for device applications.
• These findings provide fundamental insights for the development of CuSCN-based devices.