Cs₂TiI₆ (Cs₂TiI_xBr_6-x) Halide Perovskite Solar Cell and Its Point Defect Analysis

Area of Science:

• Materials Science
• Solid State Physics
• Renewable Energy

Background:

• Perovskite solar cells offer high efficiency but often contain lead.
• Developing lead-free, stable alternatives is critical for commercial viability.

Purpose of the Study:

• To design and optimize a lead-free, all-inorganic solar cell using Cs₂TiI₆ halide perovskite.
• To investigate the impact of point defects on cell performance.

Main Methods:

• Ab initio density-functional theory (DFT) calculations for electronic and optical properties.
• Numerical simulation and optimization of solar cell design.
• Analysis of point defect states and their densities.

Main Results:

• Achieved a theoretical power conversion efficiency (PCE) of 21.17% with TiO₂ and CuI transport layers.
• Cs₂TiI₆ exhibits excellent potential as a low-bandgap material.
• Deep defect states significantly degrade performance; high material quality is essential.

Conclusions:

• Cs₂TiI₆ is a promising lead-free perovskite for high-efficiency solar cells.
• Optimizing material processing is key to overcoming defect-related performance losses.
• All-inorganic Cs₂TiI₆ solar cells represent a viable path for sustainable photovoltaics.