Authors: Qiaojing Yan; Xianfeng Rui; Heng Li; Dapeng Yu; Qing Zhao
Addresses: State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China ' SK Hynix Memory Solutions, San Jose, CA, USA ' State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China ' State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China ' State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China
Abstract: Hybrid lead-halide perovskite solar cells (PSCs) have become the hot spot in photovoltaic domain since 2012. Although perovskite solar cells exhibit high power conversion efficiencies (PCE), some unsolved issues remain in the measurement of device performance, especially the abnormal hysteresis in current-voltage scan. The hysteresis phenomena result in the overstatement of the performance of PSCs during backward scan, which starts from the bias higher than open voltage and sweep to voltage below zero. In steady output, the stabilised PCE is lower than the dynamic outcome, such as the maximum power point in the I-V curve. The origin of this abnormal hysteresis is under debate. Here, we introduced a model to explain the dependence of I-V measurements on scan history. According to computational simulations using semiconductor transport theories, we found that the experimental results were consistent with the model based on the polarisation of perovskite materials. The bias-induced polarisation affects both the heterojunction resistance and the magnitude of light-generated current. By analysing current results, we supports the view that polarisation is caused by internal ion migration rather than ferroelectricity.
Keywords: perovskite solar cells; lead-halide PSCs; hysteresis; ion mobility; ferroelectricity; heterojunction resistance; polarisation; photovoltaics; scanning rate; semiconductor transport; solar energy; solar power.
International Journal of Nanomanufacturing, 2016 Vol.12 No.3/4, pp.380 - 395
Received: 03 Jul 2015
Accepted: 04 Mar 2016
Published online: 20 Sep 2016 *