Solution processed tandem polymer solar cell has drawn a great deal of attention due its low cost, ease of production and capability of harvesting solar energy more efficiently. In solution processed tandem polymer solar cell, the most challenging part is the optimization of interfacial layer. In this work, we have investigated the robustness of PEDOT:PSS/AZO/PEIE interfacial layer to develop tandem polymer solar cell. While developing triple junction polymer solar cell, temperature of second interfacial layer has also a great impact on overall device performance. Here, the performance of tandem polymer solar cell was investigated on different temperature of interfacial layer.