Significantly enhancing the performance of PEDOT: PSS/Si hybrid solar cells by simply introducing a MoOX interface layer

The formation of ohmic contact between the carrier transport layer and the electrode is necessary for the high-performance solar cells. However, in the PEDOT: PSS/Si hybrid solar cells, the low conductivity of PEDOT: PSS and the high contact barrier between PEDOT: PSS and Ag electrodes result in high contact resistance, which inhibits the improvement of cell efficiency. In this work, the above two issues were improved simultaneously by simply introducing a MoO_X interface layer between PEDOT: PSS and Ag electrodes. The detailed characterization and analytical results show that the quinoid structure of PEDOT: PSS films and the Mo⁵⁺ with metallization electricity properties increased significantly due to the interaction between PEDOT: PSS and MoO_X, reducing the resistivity of PEDOT: PSS. At the same time, the contact potential barrier was reduced due to the formation of MoO_X/Ag composite electrodes with high work function (WF). In addition, the PEDOT: PSS/MoO_X films with higher WF led to a higher built-in electric field. Due to these collaborative improvements, a PEDOT: PSS/Si solar cell with a high power conversion efficiency (PCE) of 15.02% was achieved. This work provides a new idea to modify the interface between PEDOT: PSS and Ag electrodes for improving the PCE of PEDOT: PSS/Si hybrid solar cells.