• Maximum power pointm power point
• Monolithic integration
• Photovoltaics
• Power conversion efficiency
• Silicon nanowires
• Solar cell
• Thermoelectric generator

The possibility of enhancing the power conversion efficiency of a crystalline silicon solar cell by monolithic integration with a nanostructured thermoelectric generator(TEG) is carried out. It is well known that the cell efficiency degrades with increasing temperatures, mainly due to the temperature sensitivity of the open circuit voltage (Voc); the energy loss induced by the cell heating is unavoidable as the incident spectrum is characterized by photons with energy greater than the silicon energy band gap: the excited electrons fall back to the minimum of the conduction band by the process of thermalization, yielding the excess energy to the lattice phonons. By controlling the temperature of a bottom plate, a temperature gradient is generated across the silicon nanowires (SiNWs), previously formed on the rear face by means of the metal assisted chemical etching (MACE) technique. Thanks to the Seebeck effect, a voltage drop is present between the hot side, i.e. the heated cell, and the cold bottom plate. This voltage adds to the output voltage of the solar cell, mitigating the degrading effect of temperature on Voc. The advantage of the integrated approach lies in the fact that the nanostructured TEG adds no series resistance to the solar device, diffrently from an hybrid approach which couples the two individual subsystems, i.e. the photovoltaic cell and the TEG, by an external electrical series connection, hence, adding the series resistance of the TEG to the one of the solar cell. Following the integrated approach, the fill factor remains undisputed, without affecting the overall system PCE.