Polymer modification of perovskite solar cells to increase open-circuit voltage

Organic-halide perovskites recently have emerged as a perspective material for being used in solar cells due to their unique physical properties. One of these is ionic migration, that usually is identified as an obstacle in solar cell performance because it decreases the internal stability, which leads to device degradation. However, due to the location of defect levels of migrated ions and their vacancies under the external conditions (sun or voltage), it is possible to create of p-i-n structure inside the perovskite layer. It increases the splitting quasi-fermi level and, thus, the open-circuit voltage and efficiency. Basically, the process is reversible, and without external conditions, ions migrate backward, but if ions are fixed near the boundaries by ion-conducting polymer, it will slow down or even stop ion backward migration. In this work, we are presenting the increasing of open-circuit voltage by inserting polyethylene oxide into perovskite film.