Photons from the solar spectrum carry different quantities of energy. To harvest the heat generated by the thermalization of high-energy photons, recent research proposed a hybrid photovoltaic-thermoelectric (PV-TE) structure where the excessive heat is converted into electricity via a thermoelectric generator (TEG). The addition of this TEG adds a thermal resistance which reduces the heat dissipation in the cell thus reducing the power output of the cell compared to a cell working at standard conditions. One way to limit the temperature rise in the cell as well as convert the unabsorbed low-energy photon is to develop a custom interface between the PV cell and the TEG combining both photothermal properties and high thermal conductivity. We will discuss here the different parameters to take into account in the design of this interface and its impact on the performance of the full PV-TE system. We will also look at the method of fabrication and integration of such an interface in a PV-TE system.