Comparative Analysis of Lead-Based and Lead-Free Perovskite Solar Cells

Abstract

The current study provides a comparative report on lead-based and lead-free perovskite solar cells with emphasis on efficiency, stability and dependability of operation. There are two approaches to modeling. A coupled optical-electrical model is used to study the lead-free perovskite solar cell, whereas a numerical optical model is used to study lead based materials under the same illumination conditions. The findings indicate that the lead-free perovskite (Cs₂AgBiBr₆) can be able to attain a maximum simulated efficiency of approximately 21% in an optimal thickness of 75 nm. But the electrical performance is very low with the current density of approximately 0.026 mA/cm² and efficiency of only 0.00051% in the actual conditions. Contrary to this, lead-based compounds like FAPbI₃ and MAPbI₃ can be optically absorbed to 850 nm or higher with much higher ideal current densities with FAPbI₃ absorbing to 1.15 × 10⁻¹³ mA/cm². Carrier generation and deep penetration of the light is equally better in lead/based materials. There are however toxicity and stability problems with them. The research proves that there is a definite trade-off between high efficiency and environmental safety and therefore more studies are required in an effort of ensuring better lead-free material can be used practically.