The recent rise in power conversion efficiencies reported for perovskite solar cells has been a remarkable development in photovoltaics research. It is now pressing that the technology transitions from a research phenomenon to a real-world deployable device: this will require both robust methods for efficiency measurement, and accurate models for performance variation at different conditions. However, the generally slow response of perovskite solar cells to changes in voltage bias and irradiance, and the susceptibility of these cells to degradation, presents significant challenges. In this paper, we investigate current and voltage stabilisation of planar CH3NH3PbI3 perovskite solar cells and observe remarkably large variations in stabilisation time depending on exposure history. To address this, we demonstrate a dynamic approach that continues device pre-conditioning until pre-determined stability criteria are met. This approach is then employed to obtain measurements of short-circuit current and open-circuit voltage temperature coefficients under quasi-steady-state conditions for perovskite devices and a control monocrystalline silicon cell. The obtained open-circuit voltage temperature coefficient for the perovskite is −2700 ppm/°C, which interestingly, is similar to typically reported values for crystalline silicon devices. It is shown that the implemented approach can successfully differentiate between transient responses to the onset of illumination and true temperature related changes. We also find new manifestations of the complex transient processes that occur in perovskite devices. These observations highlight the importance of sophisticated characterisation approaches for correct characterisation of the performance of perovskite solar cells.
|Number of pages||12|
|Journal||Progress in Photovoltaics: Research and Applications|
|Publication status||Published - 1 Jul 2017|
- temperature dependence