Researchers establish strain relaxation for stable quasi-2D perovskite solar cells

• The harvesting of solar energy has actually received extensive interest. Among all the light collecting devices, perovskite solar cells (PSC) attract attention in the photovoltaic field as a result of their benefits, consisting of excellent photovoltaic properties, inexpensive, as well as easy handling.

As the outcome of years of study, the power conversion effectiveness of PSC has reached the requirement of commercialization. Presently, the primary obstacle to its additional development is the unsuitable stability under external stress.

Recently, Prof. Zhou Huiqiong's group from National Center for Nanoscience and Technology (NCSNT) of the Chinese Academy of Sciences (CAS) has established a strain relaxation method to study the impact of residual strain on properties of quasi-two-dimensional (2D) perovskites. The relevant study results were published online in Angewandte Chemie International Edition.

The introduction of hydrophobic spacer cations makes quasi-2D perovskites more stable compared to typical 3D perovskites, however the stability of perovskites continues to be disappointing. Residual strain is carefully pertaining to the crystallographic properties, which in turn can substantially influence the photovoltaic or pv properties and also stability of perovskites.

The scientists explored the residual strain in quasi-2D perovskite with blended spacer cations by X-ray diffraction (XRD) as well as atomic pressure microscope (AFM). They found that there is serious tensile strain along the out-of-plane instructions in excellent perovskite film, causing poor crystallinity and not enough stability issues. With an appropriate structure of spacer cations, the tensile strain is properly released.

In summary, maximizing the spacer cations could control the residual strain in quasi-2D perovskite, further improving the inherent stability of perovskites. This work gives a practical technique for regulating the solar properties and also enhancing the stability of perovskite-based solar devices.