Specificities of the Thermal Behavior of Current and Emerging Photovoltaic Technologies

This chapter describes the specificities of the thermal behavior of different photovoltaic technologies. In standard silicon solar cells, the temperature coefficients are mainly driven by the open-circuit voltage . It is argued that the upcoming deployment of the passivated emitter and rear cell (PERC) technology will be beneficial for the temperature sensitivities and the operating temperatures of modules. Silicon heterojunction (SHJ) solar cells also benefit from large open-circuit voltages which result in advantageous temperature coefficients. The thermal behavior of SHJ devices is also driven by specific mechanisms such as thermionic carrier transport which results in non-linear temperature variations of the fill factor and subsequently of the conversion efficiency. An analysis of the temperature sensitivity of solar cells made of compensated silicon is presented. The specificities of the short-term thermal behavior of a-Si solar cells are discussed. A review of the literature investigating the thermal behavior of perovskite -based devices is proposed. Despite the discrepancies, several important mechanisms are highlighted (e.g. the strong temperature dependence of carrier transport which generally results in a maximum of the conversion efficiency around room temperature). The particularities in terms of thermal behavior of multi-junction solar cells and concentrator devices are discussed. Finally, the analysis is extended to thermophotovoltaic applications where the operating conditions are significantly different from “standard” photovoltaics (different heat sources and angle mismatch, opportunity of low-energy photon recycling , etc.).