Temperature Dependent Characteristics of Perovskite Solar Cells

In this work we report the characterization of perovskite solar cells with mesoscopic TiO2/Al2O3/NiO/carbon architecture by analyzing the dependence of photovoltaic parameters on temperature and illumination intensity. This perovskite device shows impressive power conversion efficiency at room temperature (>14%) and at low temperature of 80K (>5%). This enables unequivocal identification of the contribution of CH3NH3PbI3 to construction of the built-in electric field, and thus, the temperature dependent photovoltaic parameters. The typical feature of this type solar cell is that open-circuit voltage follows behaviour of the dielectric constant of CH3NH3PbI3. In addition, the dependence of current on light intensity shifts from the space-charge-limited to diffusion-limited mechanisms as increasing temperature. By using the observed significant short-circuit current density of 12.76mA cm(-2) at 80K the exciton-binding energy of CH3NH3PbI3 is evaluated to be less 6.9 meV in an operating device, which can be further verified with Elliott's formula.