Strain-gradient-induced modulation of photovoltaic efficiency

In this paper, we show that strain gradients can greatly affect the total photovoltaic efficiency of perovskite solar cells. By adding the flexophotovoltaic effect on top of the standard photovoltaic effect of semiconductor junctions, the total output of perovskite photovoltaic devices can be either completely suppressed or greatly enhanced, depending on the relative sign of the strain gradient with respect to the semiconductor junction polarity. The results thus indicate that, whether as a threat to efficiency or as a means to enhance it, strain gradients can greatly affect the performance of perovskite solar cells, and flexoelectric engineering is thus an indispensable step in the pursuit of maximal photovoltaic efficiency.