Energetic Barriers to Interfacial Charge Transfer and Ion Movement in Perovskite Solar Cells. Issue 21 (21st September 2017) - Sadollahkhani, Azar
Abstract: Highly efficient perovskite solar cells have been characterized by current‐density/voltage measurements in the dark at varied scan rates. The results were compared to the solar cells without a hole‐transporting layer to investigate the role of ultrathin hole‐transporting layers in solar‐cell function. The parameters of internal voltage, diode ideality factor, capacitive current, and capacitance were calculated from the current‐density/voltage response of the cells in the dark. The results show that the absence of the hole‐transporting layer can cause a large recombination current within the depletion region at the gold contact/perovskite interface, and thus affects the cell performance. Abstract : Ionic movement : Application of a forward bias to the cell leads to ion movement. Decreasing bias voltage is expected to reduce the current; however, the ion current results in an overall increase in measured current. Below the threshold voltage for ion movement typical diode behavior is observed even though this increases the depletion layer and concomitantly decreases the charge concentration, charge extraction, and charge recombination.