An important part of modern photovoltaic (PV) systems is the so-called power electronics. Its two main goals are to convert the power output of a PV module to the desired voltage, current, and frequency, and to control the operation point of the PV modules for maximum power harvesting. The power electronics and their behavior within a hybrid, smart AC-DC system is currently being studied within the emerging field of photovoltatronics [1]. This coincided with (sub-) module-level power electronics being one of the fastest-growing market segments in the solar industry, namely power converters designed to be used for (a part within) one single PV module. It comes with advantages, such as increased shade tolerance, energy yield, module reliability, safety, and design flexibility. However, module-level converters are nowadays both bulky and expensive, with most of the volume being occupied by passive devices such as inductors and capacitors. These passives also represent a significant share of the converter cost. On top of this, power converters are still the least reliable part of a PV system [2].

To achieve a high performance in sub-module power conditioning circuits, it is important that power converters are designed in accordance with the photovoltaic (PV) cell impedance at the input. Taking this one step further, exploiting the impedance of cell strings could even support novel power conditioning approaches in PV modules. In this work, we characterize the impedance of eight single-cell laminates based on different industrial c-Si PV cell architectures. This characterization is carried out by impedance spectroscopy in dark conditions at room temperature, and the capacitive and inductive effects are evaluated through equivalent model fitting. By comparing the results for the different laminates, it is revealed how the cell design affects its impedance. Our experiments show that the PN junction capacitance at maximum power point varies for the different cells between 0.30 and 45.6 μF/cm². The two main factors contributing to a high PV cell capacitance at maximum power point are (i) a low wafer dopant concentration and (ii) a high maximum power point voltage. In high-efficiency c-Si PV cells that will be fabricated in the coming years, increasing capacitances are expected for operation near the maximum power point. Furthermore, the single-cell laminates exhibit inductances between 63 and 130 nH, and our results indicate that the inductance is mostly affected by the number of busbars and the geometry of the metal contacts.