Authors: Maria Hadjipanayi | Tom Aernouts | Matthew Norton | Elias Peraticos | Aránzazu Aguirre | Anurag Krishna | Vasiliki Paraskeva | Santhosh Ramesh | Rita Ebner | Andreas Othonos | Alexandros Themistokleous | Sophia C. Hayes | George E. Georghiou
Source:  (article, 2023-12-18)
Field: Materials Science — Materials Chemistry

Outdoor stability testing of perovskite mini - modules: long-term analysis &amp;lt;p&amp;gt;Perovskite solar cells have been attracting increasing attention in recent years due to their rapid progress with record efficiency of 26.1% for single junction and 33.9% for tandem devices respectively [1]. The biggest concern that impedes the application of perovskites and poses tremendous challenges for their commercialization is their long-term stability under operation [2]. Even if now perovskites are passing standardized protocols (IEC 61215) and ISOS procedures, those tests cannot resemble the outdoor operational conditions with day-night cycles and continuous change in temperature and irradiance levels. Although outdoor stability testing has been reported for different types of perovskite devices so far [3], [4] there is still a lack of quantitatively precise information about the diurnal trend in long-term performance of perovskites under outdoor conditions.&amp;lt;/p&amp;gt;\n&amp;lt;p&amp;gt;In this work, several perovskite and perovskite on Silicon tandem mini-modules were extensively investigated outdoors at real environmental conditions for a duration of up to two years and indoors using a range of advanced optoelectronic methods to set-up a complete optical and electrical characterization of perovskite devices. Characterization methods of spatially - resolved Electroluminescence/Photoluminescence, Dark Lock-In Thermography, Raman and Ultrafast spectroscopies have been utilized for this purpose. Outdoor testing for several months in the field demonstrated the impact of irradiance and temperature on the major electrical parameters of the devices. Interplay of metastability and temperature effects were detected in the output power temperature coefficients results while agreement was found between indoor laboratory tests and outdoor results for voltage temperature coefficients.&amp;lt;/p&amp;gt;\n&amp;lt;p&amp;gt;Diurnal performance degradation and recovery overnight were calculated for the first time outdoors. Seasonality effects in the diurnal changes are discussed demonstrating the values of performance recovery overnight and diurnal performance degradation as well as the degradation-to-recovery ratio at different environmental conditions. The diurnal changes in performance, current and voltage have been calculated and facilitated on the understanding of irradiance effects on the major electrical parameters of the perovskite samples. A data-driven predictive model has been utilized for predicting the output power time-series of perovskites.&amp;lt;/p&amp;gt;\n&amp;lt;p&amp;gt;Moreover, several optoelectronic and spectroscopic methods such as Ultrafast and Raman spectroscopies and Dark Lock-In-Thermography methods have been employed to understand changes in carrier relaxation dynamics and chemical properties after outdoor exposure as well as hotspot evolution in the devices under test. Results demonstrated FA decomposition products and changes in carrier relaxation mechanisms in Raman and Ultrafast methods respectively. Finally, Dark Lock-In Thermography method revealed hotspot evolution in both perovskite active and interconnection areas of the cell.&amp;lt;/p&amp;gt; Term (time) ; Stability (learning theory) ; Computer science ; Reliability engineering ; Engineering ; Physics ; Machine learning Thermal Expansion and Ionic Conductivity ; Perovskite Materials and Applications ; Advancements in Solid Oxide Fuel Cells