Eradication of non-capacitive effects with potassium incorporation in perovskite solar cells

Abstract

The presence of redox reactions due to slow-moving ions at perovskite/contact interfaces is a major concern for the long-term stability of perovskite solar cells. In this work, we have evidently demonstrated the contribution of K+ ions on the removal of these non-capacitive effects that primarily accelerate the degradation mechanism in the devices. The intermittent current-voltage characteristics at the short-circuit conditions elucidate the role of K+ ions on reducing the rapid degradation at the interfaces due to the chemical reactivity of the accumulated ions by eliminating the burn-in decay in the photocurrent. Dark current-voltage measurements, time-resolved staircase voltammetry, and electrochemical impedance spectroscopy verified that both capacitive and non-capacitive currents, consequence of slow ion migration, are reduced by the incorporation of K+. Thus, this work signifies how K+ incorporation diminishes the internal degradation and enhances intrinsic stability of perovskite solar cells.