2-Dimensional Additive Engineered Perovskite for Highly Efficient Tandem Solar Cells
2-Dimensional Additive Engineered Perovskite
for Highly Efficient Tandem Solar Cells
Dong Hoe Kim
Department of Materials Science and Engineering, Korea University, Republic of Korea
The tandem solar cells, which based on dual junctions combining wide-bandgap top cells (e.g., ~1.7–1.9 eV) and narrow-bandgap bottom cells (e.g., ~0.9–1.3 eV) are considered as an effective strategy to overcome the Schokley-Queisser (S-Q) limit (~31-33%) of single-junction solar cells. Organic-inorganic metal halide perovskite (PVSK) materials is one of the most promising candidates for the top- and bottom-cell in tandem devices (e.g., PVSK/PVSK, PVSK/Cu(In,Ga)Se2 (CIGS), and PVSK/Si) owing to their flexible bandgap-tunability, low-cost processing, and various formation routes like spin-coating, blade-coating, vacuum deposition.
One of the critical challenges in developing tandem devices using perovskite is to prepare highly efficient wide-bandgap perovskite solar cells (PSCs) for top-cells. The formation of a 2-dimensional (2D) passivation layer using large organic cations (e.g., butylammonium or phenethylammonium) has been considered one of the most promising approaches. However, some challenges have led to lower performance in 3D/2D mixed PVSK due to the limitation of charge transport caused by the long and bulky organic cation from the 2D passivation layer.
This lecture introduces the various strategies like cation/anion engineering in 2D parts and dipole engineering to demonstrate a highly efficient 3D/2D PSCs with 1.68eV wide bandgap. Based on our strategies, we finally demonstrated highly efficient and stable PVSK based tandem solar cells with various kinds of bottom cells combination like CIGS, and Si.