Utilizing Impedance Spectroscopy to Optimize the Fabrication of Semitransparent Agrivoltaics

Over the next two decades, rising demands for food, energy, and clean water are expected due to current consumption trends and steady population growth. Agrivoltaic systems, which combine solar energy production with agricultural production in areas with high solar irradiation, offer a creative way to help meet these increasing demands. In previous work, a fully solution-processible method for fabricating semi-transparent solar cells was developed. However, the efficiencies of these research-grade organic photovoltaics (OPVs) reached only 2.95×10-07%. For future greenhouse use, efficiencies of 1-2% are desired. This study investigates the use of circuit analysis to enhance the performance of OPV devices. The thickness of each layer of an OPV device plays a critical role in determining the device's series resistance, which in turn affects its overall efficiency and performance. By employing Bode and Nyquist plots, the impedance characteristics of OPVs were examined to pinpoint reductions in series resistance before and after adjusting the thickness of the device’s layers. For the thickness adjustments of each layer, atomic force microscopy was used to reach the optimal thicknesses for OPV functionality. Furthermore, capacitance and shunt resistance were analyzed in relation to potential recombination effects. The extracted parameters were used to validate experimental methods aimed at reducing series resistance and addressing performance issues, ultimately improving the efficiency of the OPV devices to 0.05%. Future work will explore the effects shading has on lettuce plant growth using newly constructed evaluation platforms fitted with sensors. Sensor data will be analyzed to compare plant growth under purchased silicon panels, fabricated OPV panels, and full sun. An agricultural specialist would then evaluate the lettuce plants grown under the OPV panels to quantify the economic impact of using semi-transparent agrivoltaic systems to grow shade-tolerant crops.