Taking their cue from the humble leaf, researchers have used microscopic folds on the surface of photovoltaic material to significantly increase the power output of flexible, low-cost solar cells.
The key requirements to construct highly foldable solar cells, including structure design based on tuning the neutral axis plane, and adopting flexible alternatives including substrates, transparent electrodes and absorbers, are intensively discussed.
In the end, some perspectives for the future development of foldable solar cells, especially the standard folding procedure, improvement in the folding endurance through revealing failure mechanism, are provided.
When the solar modules subjected to folding, the Jsc started to decrease and gradually saturated at around 4 mA cm -2 after 10 cycles of folding/unfolding, while the Voc almost remained constant throughout 40 times folding/unfolding, as shown in Figure 3D. Foldable solar cells with crease in the predesigned place.
Why are foldable solar cells important?
However, due to the advantages of size compactness and shape transformation, they have unique applications such as portable and wearable electricity supplier, as well as building, transportation and agriculture integrated photovoltaics. The development of highly foldable and efficient solar cells is of great importance.
Besides the substrates and transparent electrodes, the mechanical properties of absorber layer also significantly influence the foldability of solar cells. Firstly, the mechanical properties, especially the Young's module and hardness of different kinds of absorber are various.
Do foldable solar cells have a low PCE?
By now, the foldable solar cells generally exhibit low PCE and inferior folding stability compared with that of normal bendable solar cells.