Trade-Off Between Toxicity and Efficiency in Tin- versus Lead-Based Halide Perovskites

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Lead-based perovskites offer high efficiency but pose toxicity concerns.
• Non-toxic alternatives are crucial for widespread perovskite solar cell adoption.

Purpose of the Study:

• To investigate the trade-off between toxicity and efficiency in tin-based halide perovskites compared to lead-based ones.
• To understand the fundamental reasons behind efficiency differences.

Main Methods:

• Comparative analysis of recombination mechanisms in tin-based (CsSnI3) and lead-based (CsPbI3) halide perovskites.
• Investigation of band alignment and its effect on non-radiative recombination.

Main Results:

• Tin-based perovskites exhibit a dominant non-radiative recombination center different from lead-based ones.
• The non-radiative capture coefficient in CsSnI3 is significantly higher (by an order of magnitude) than in CsPbI3.
• Band alignment differences are identified as the cause for varying recombination rates.

Conclusions:

• A direct trade-off exists between achieving non-toxic and highly efficient perovskite solar cells with current tin-based materials.
• Further research into halide perovskites beyond lead and tin is essential for developing efficient and environmentally friendly solar cells.