PbS Colloidal Quantum Dot Solar Cells with Organic Hole Transport Layers for Enhanced Carrier Separation and Ambient Stability

We have investigated poly (3-hexylthiophene) (P3HT) as a hole transport material interfacing PbS quantum dot and anode, and found that carrier separation is enhanced by increasing carrier concentration and mobility of P3HT. In addition, the ambient stability of PbS colloidal quantum dot solar cells are shown to be improved by surface oxidation of P3HT. Comparing with MoO₃ anode interfacing material, P3HT performs better with controllable ambient stability. Electrode interfacing material should enable appropriate internal force for efficient carrier separation and enough carrier mobility to minimize carrier losses, which needs to provide a surface stabilization strategy to prevent degradation induced by ambient oxidation.