Elucidating the evolution of the current-voltage characteristics of planar organometal halide perovskite solar cells to an S-shape at low temperature

• Published in: Solar energy materials and solar cells Vol. 157; pp. 981 - 988
• Main Authors: Xu, Fei, Zhu, Jiabin, Cao, Runan, Ge, Sheng, Wang, Wenzhen, Xu, Haitao, Xu, Run, Wu, Yanglin, Gao, Ming, Ma, Zhongquan, Hong, Feng, Jiang, Zuimin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2016
• Subjects: Current-voltage characteristics; Perovskite solar cell; Temperature dependence; Temperature dependence; Current-voltage characteristics; Perovskite solar cell
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2016.08.011

The temperature dependence of initial transient current-voltage (I-V) characteristic of planar perovskite solar cell by one-step solution process is investigated. An S-shaped I-V characteristic emerges in response to low temperature and the photovoltaic parameters drop dramatically. This is mainly attributed to the increasing amount of negative charges accumulating in the TiO2/CH3NH3PbI3 interface region and the reduced built-in field separating the photo-generated carriers in the absorber layer. The influence of negative charge accumulation can be represented by two extra diodes that are in series with a conventional solar cell circuit model at low temperature whereas it acts as a resistor with low resistivity above room temperature. These findings help to understand the charge transport mechanism in perovskite solar cells. •Photovoltaic performance of planar perovskite solar cell degrades at low temperature.•A three-diode equivalent circuit fits the S-shaped I-V characteristic.•Attributed to negative charges accumulating in the TiO2/CH3NH3PbI3 interface region.