Tin-based perovskite solar cells with a homogeneous buried interface

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Tin-based perovskite solar cells (TPSCs) are promising non-toxic alternatives to lead-based photovoltaics.
• Current TPSCs face challenges in performance and stability due to issues with hole transport layers and buried interfaces.
• Existing inverted TPSC architectures have achieved power conversion efficiencies (PCEs) exceeding 16%.

Purpose of the Study:

• To enhance the performance and stability of inverted tin-based perovskite solar cells (TPSCs).
• To address limitations in hole extraction and perovskite film quality in TPSCs.
• To develop a scalable strategy for high-efficiency, stable TPSCs.

Main Methods:

• A novel molecular film, (E)-(2-(4',5'-bis(4-(bis(4-methoxyphenyl)amino)phenyl)-[2,2'-bithiophen]-5-yl)-1-cyanovinyl)phosphonic acid, was introduced at the buried interface.
• This molecular film optimized hole transport layers and improved the buried interface in inverted TPSCs.
• The strategy guided the growth of uniform, high-quality Sn-based perovskite films with reduced defect density.

Main Results:

• A record PCE of 17.89% was achieved for small-area inverted TPSCs (certified 17.71%).
• The molecular film facilitated enhanced hole extraction and minimized non-radiative recombination losses.
• Encapsulated devices maintained over 95% of initial PCE after 1,344 hours of shelf storage and 94% after 1,550 hours of operation.
• A record PCE of 14.40% was achieved for 1 cm² TPSCs, demonstrating scalability.

Conclusions:

• The developed molecular film strategy effectively optimizes hole transport and buried interfaces in inverted TPSCs.
• This approach leads to significant improvements in both efficiency and operational stability for tin-based perovskite solar cells.
• The demonstrated scalability suggests a viable pathway for the commercialization of high-performance, environmentally friendly solar technology.