Approaching 24% Efficiency in Four-Terminal Perovskite/CZTSSe Tandem Solar Cells Using Diphenylammonium Chloride Additive-Based Wide-Bandgap Perovskite Absorber.

Summary: Imagine stacking two solar panels on top of each other to catch more sunlight than a single panel ever could. That is the concept behind "tandem" solar cells. In this study, researchers combined a top layer made of a material called Perovskite with a bottom layer made of CZTSSe (a mix of copper, zinc, tin, sulfur, and selenium). To make the top layer work even better, they added a "secret ingredient"—a salt called DPACl. This additive smoothed out the microscopic structure of the solar cell, allowing electricity to flow more freely. The result? A super-efficient tandem cell that converts nearly 24% of sunlight into power and stays durable for over 1,000 hours.