Research Blogs
Characterization Suite 4.5 helps researchers get more from Paios, Phelos and Litos
Characterization Suite 4.5 enhances the software environment for Paios, Phelos and Litos, helping researchers move faster from measurement to interpretation. With new post-processing tools, expanded measurement capabilities, improved stability workflows and a stronger 64-bit software foundation, the release supports more efficient OLED, solar cell, photodetector and ageing studies.
Reverse-bias Stressing of Perovskite Solar Cells
This study shows that reverse-bias in perovskite solar cells can trigger degradation even before breakdown occurs. Rather than immediate shunting, milder reverse-bias stress leads to progressive recombination-driven performance loss and reversible dark-spot formation, highlighting a key commercialization challenge under realistic operating conditions.
How to quantify Non-radiative voltage losses and recombination in solar cells
The open-circuit voltage (Voc) is the electrical potential difference between the two terminals of a solar cell, when there is no external load applied, hence no electric current flows. Correspondingly, this means that, when a voltage equivalent to the Voc is applied to the terminals of the solar cell, the recombination current (Jrec, which typically follows a non-ideal diode equation) and the photocurrent (Jph, the current generated by illuminating the solar cell) are equal, hence the net current is zero (Jrec=Jph at V= Voc).
Solar cells often present also non-radiative recombination mechanisms, in addition to the radiative one, as a result of poor material quality and non-idealities. To increase the Voc and thus potentially the power conversion efficiency, it is necessary to minimize the ΔVoc,nrad. It is, therefore, necessary to quantify the total loss and determine its origin.
Electroluminescence (EL) and photoluminescence quantum yield (PLQY) allow to directly extract the ΔVoc,nrad for thin-film solar cells such as perovskite solar cells, kesterite, perovskite, organic, or quantum dot. solar cells.
After quantifying the losses, the combination of capacitance-voltage (CV), temperature-dependent voltage characteristics (JV-T), and capacitance-frequency (Cf-T) measurements are essential to identify the recombination mechanisms.