3:15 PM - 3:30 PM
▲ [11p-N322-9] Tin flexible perovskite solar cells with efficiency approaching 10%
Keywords:Flexible perovskite solar cells, Tin perovskite, Energy alignment
Recently, perovskite solar cell devices with superior efficiency have been reported with improved efficiencies were revealed upon light soaking phenomenon. Herein, we fabricated a few types of perovskite of lead based, tin based and tin-lead based flexible perovskite solar cells. The light was illuminated upon the devices via MPPT experiment and also during biasing in PCE measurement which took total duration of 1 hour. Interestingly, the tin based devices demonstrated high stability and significant improvement in efficiency during light soaking experiment in comparison to the other types of perovskite solar cells. The efficiency of the flexible tin perovskite solar cells approaching 10% was obtained with improvement in the fill factor (0.6) and the Voc (0.74 V). The fabricated devices consisted of flexible PET ITO substrates, PEDOT:PSS hole transport layers, EDA passivated perovskite films, C60 electron transport layer, BCP hole blocking layer and silver electrodes. Thus, we investigated the reason behind this improvement by hypothesizing the effect of light soaking on energy level modification of the multilayer films before and after the light soaking. In order to understand this effect, we investigated the properties of the perovskite films before and after light soaking through photo-luminescence, UV-Vis and PYS experiments. The findings showed that the energy level of the perovskite films were slightly modified to favor the charge transport and extraction from the perovskite films to the charge collection layers, by reducing the mismatched offset. In conclusion, this interesting phenomena sheds light on the applicable strategies in order to enhance the efficiency of the flexible perovskite solar cells via strategic energy alignment configurations in perovskite solar cells.