Organic solar cells (OSCs) have emerged as promising
energy harvesters
owing to their outstanding optoelectronic properties, approaching
a maximum power conversion efficiency of over 19%. However, single-junction
OSCs have limitations in improving efficiency owing to transmission
and thermalization losses. To alleviate these drawbacks, a tandem
configuration was devised, involving the stacking of two subcells
to absorb a broad solar spectrum and minimize transmission and thermalization
losses. This tandem strategy is not limited to organic/organic-based
systems but extends to organic/perovskite-, organic/colloidal quantum
dot (CQD)-, and organic/amorphous silicon (a-Si)-based tandem solar
cells (TSCs). This Review commences with a brief overview of developments
in organic photoabsorbers and introduces the general concepts of TSCs.
Then, we summarize recent research endeavors for organic/organic-,
organic/perovskite-, organic/CQD-, and organic/a-Si-based hybrid TSCs.
Lastly, the Review concludes by offering insights and prospects for
enhancing the performance of organic-based hybrid TSCs by ≥25%.