Outdoor testing identifies factors contributing to perovskite solar cell degradation
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Summary
Tests conducted by a research team in outdoor environments in Spain and Poland have demonstrated a strong correlation between perovskite solar cell degradation and the combined effects of climatic and operating conditions. The scientists found that open-circuit operation accelerates degradation, whereas operation at the maximum power point and under short-circuit conditions has a lower impact.
<p class="p1"><span class="s1">Tests conducted by a research team in outdoor environments in Spain and Poland have demonstrated a strong correlation between perovskite solar cell degradation and the combined effects of climatic and operating conditions. The scientists found that open-circuit operation accelerates degradation, whereas operation at the maximum power point and under short-circuit conditions has a lower impact.</span></p><p>An international research team investigated the performance of inverted perovskite solar cells under outdoor conditions in Spain and Poland, comparing the results with those obtained through commonly used accelerated aging protocols.</p>
<p>The novelty of their work lies in correlating accelerated degradation test parameters with real-world observations to more accurately identify the factors that contribute to perovskite PV device degradation.</p>
<p>“Potential investors and industry stakeholders require a reliable benchmark to assess the technology’s viability and long-term potential,” the scientists explained. “It is important to emphasize that there is currently no conclusive evidence demonstrating that failure to pass such accelerated tests directly predicts device lifetime under real outdoor conditions, typically targeted at 20–25 years for photovoltaic applications.”</p>
<p>The group tested inverted perovskite solar cells encapsulated with polyisobutylene (PIB) for 173 days at two facilities: one in Madrid, Spain, which has a hot-summer Mediterranean climate; and the other in Gdańsk, Poland, characterized by a hot-summer humid continental climate.</p>
<p>The cells were built with a substrate made of glass and indium tin oxide (ITO), a hole transport layer (HTL) based on <a href="https://www.pv-magazine.com/2021/03/29/18-3-efficient-perovskite-solar-cell-for-automatic-light-adjustment/" rel="noopener" target="_blank">poly(triarylamine) (PTAA</a>), a perovskite absorber, <span dir="ltr">an electron transport layer (ETL) relying on <span class="aCOpRe">phenyl-C<sub>61</sub>-butyric acid methyl ester (PCBM)</span>, a bathocuproine (BCP) buffer layer, and a silver (Ag) metal contact. </span></p>
<p>For the outdoor testing, the scientists followed the ISOS-O-2 protocol, performing current-voltage (J-V) measurements every 60 minutes in Gdańsk and every 10 minutes in Madrid. The cells in Spain were mounted on a solar-tracking system, while those in Poland were installed on a fixed structure.</p>
<p>The analysis revealed a big difference in long-term performance between the cells tested in Poland, which maintained a relatively stable performance throughout the exposure period, and those operating in Spain, which suffered from a constant decline.”</p>
<p>“This difference in device behavior may be influenced by various factors, including climate conditions, operating mode, mounting configuration, and measurement frequency, as the tests were conducted under different setups,” they specified.</p>
<p>They also found that the main factors affecting cell performance are absorber degradation, bulk defects and interfacial losses. Further analysis conducted in Gdańsk showed that the cellG open-circuit (OC) accelerates degradation “strongly,” while maximum power point (MPP) and short-circuit (SC) were found to have the least impact.</p>
<p>The outdoor degradation mode was found to be similar to that detected through light soaking, with no “noticeable” extraction-related issues being reported.</p>
<p>Their findings can be found in the study “<span class="title-text"><a href="https://www.sciencedirect.com/science/article/pii/S0038092X25008941#f0005" rel="noopener" target="_blank">Degradation of perovskite solar cells: Insights from accelerated testing versus outdoor aging in two climate zones</a>,” published in <em>Solar Energy</em>. The research team comprised scientists from the Gdańsk University of Technology in Poland and the Universidad Rey Juan Carlos in Spain. </span></p>
<p>“These findings highlight the necessity of consistent measurement methodologies, as factors such as sun-tracking, specific operating conditions, and JV scan frequency can influence outdoor stability assessments,” they concluded.</p>