Remnant tensile strain in the perovskite films induced in the thermal annealing step is a known source of material and device instabilities. Here Xue et al. use a thermal expandable hole transporting layer to compensate the strain and result in most stable wide-bandgap perovskite solar cells so far.
- Ding-Jiang Xue
- Yi Hou
- Edward H. Sargent