Performance Analysis and Thermal Reliability Study of Multilayer Organic Solar Cells

The progress in organic solar cell (OSC) technology mainly focuses on improving the power conversion efficiency (PCE), longer lifetime and the development of scalable cost-effective manufacturing. In this paper, the impact of P3HT layer inserted between PEDOT:PSS hole transport layer (HTL) and P3HT:PCBM active layer has been comprehensively studied. The comparative analysis of the proposed OSC structure with the conventional OSC illustrates that, the multilayer structure significantly improves the short circuit current density (J
_SC
), fill factor (FF) and PCE of the device. This improvement in the device performance is mainly because of the increased photo absorption, reduction in the recombination losses due to improved vertical phase gradient and the efficient collection of photogenerated charge carriers at the electrodes. In addition to this, in order to determine the impact of thermal stress on the device performance, the thermal reliability study on the proposed multilayer OSC and the conventional OSC has been carried out. It has been found that, with annealing at 140 °C temperature for 10 minutes duration, the maximum PCE of 3.27% and 2.44% has been achieved for proposed multilayer OSC and the conventional OSC respectively. It has also been observed that, in comparison to conventional OSC the proposed multilayer OSC is less susceptible to the thermal degradation. Thus, the proposed multilayer OSC not only improves the device performance but also exhibits better thermal stability under different thermal conditions.