Multi-Influences of Ionic Migration on Illumination-Dependent Electrical Performances of Inverted Perovskite Solar Cells

作者：Liu, Jie; Yin, Xingtian^*; Liu, Xiaobin; Que, Meidan; Que, Wenxiu^*

来源：Journal of Physical Chemistry C, 2017, 121(29): 16051-16057.

DOI：10.1021/acs.jpcc.7b06329

• METHYLAMMONIUM LEAD IODIDE
• I-V HYSTERESIS
• ANOMALOUS HYSTERESIS
• HOLE-CONDUCTOR
• EFFICIENCY
• ORIGIN

ZnO films are employed as the electron transport layers for perovskite solar cells. Such a device exhibits an ultralong time increase in V-oc (similar to 100 s) and j(sc) (similar to 1000 s) and a weakening hysteresis under continuous illumination. Besides, a slow (similar to 20 s) V-oc decay when illumination is switched off is also observed. The electrical measurements performed under illumination and under voltage bias before being illuminated, suggest the influences of ionic accumulation/redistribution in causing above phenomena. Ionic accumulation happening in dark and ionic redistribution under illumination lead to band bending which affects the excitons separation and carrier extraction. These can account for the ultralong time increase in V-oc, and J(sc) as well as the slow V-oc, decay. Also, the time-dependent. photocurrent response under stepwise scan proves the presence of a capacitive effect in the device which can be dramatically reduced by the ionic redistribution under illumination. The ionic redistribution is also an important reason for the weakening hysteresis.

• 出版日期2017-7-27
• 单位西安交通大学