Tandem organic solar cells revisited

Artifact Interpretation of Spectral Response Measurements on Two‐Terminal Multijunction Solar Cells

“…On the contrary, it is commonly expected and often observed that the EQE measured in the dark mainly outlines the overlap between the EQE spectra of all component subcells. Although such expectation was not always met as shown in literature, the result in Figure a is worth extra attention. In this case, the discrepancy between this simulation and the aforementioned expectation originates from a shunt leakage overestimated by the parameters of illuminated diodes.…”

Precise Characterization of Performance Metrics of Organic Solar Cells

“…According to the standards and the checklist suggested by recent correspondences, it is strongly recommended to report the following aspects for new and best‐performing single‐junction organic or perovskite solar cells: i) the detailed characterization conditions, such as the types and calibrations of the solar simulators and reference cells, and the temperature and atmosphere of measurement; ii) the scanning parameters and the J–V curves in both scan directions; iii) the definition of cell area and the use of aperture; iv) the statistical values and the corresponding error bars of the devices measured at each condition; v) the stability of the devices, particularly for perovskite solar cells; and vi) a certification report by an independent institution.…”

“…It can be seen that tremendous improvements have been achieved, and that the highest published PCEs have recently surpassed 12% and 22% for organic and perovskite solar cells, respectively. Along with the rapid advances in these fields, the issue of erroneous efficiency reports in organic and emerging perovskite photovoltaic technologies is currently receiving growing attention, which has driven the publication of several editorials in the Nature family of research journals and editorials/commentaries/opinions in these and other specialized journals . Although the efficiency records are continually broken over time, the photovoltaic parameters of new solar cells often need to be evaluated by an independent institute for a meaningful comparison of PCE values from different research institutions and countries.…”

“…Along with the rapid advances in these fields, the issue of erroneous efficiency reports in organic and emerging perovskite photovoltaic technologies is currently receiving growing attention, which has driven the publication of several editorials in the Nature family of research journals [27][28][29][30][31][32] and editorials/commentaries/opinions in these and other specialized journals. [16,17,[33][34][35][36][37][38][39][40][41][42][43][44][45] Although the efficiency records are continually broken over time, the photovoltaic parameters of new solar cells often need to be evaluated by an independent institute for a meaningful comparison of PCE values from different research institutions and countries. Particularly, the solar cells with record PCEs should be strictly certified by one of a few worldwide accredited laboratories; [46] for instance, the National Renewable Energy Laboratory (NREL) and the Newport Corporation in the United States, the National Institute of Advanced Industrial Science and Technology (AIST) in Japan, and the Fraunhofer Institute for Solar Energy (ISE) Laboratory in Germany, which hold ISO/IEC 17025 accreditation under the International Laboratory Accreditation Cooperation Mutual Recognition Arrangement (ILAC MRA).…”

Organic tandem solar cells: How impedance analyses can improve the quality of external quantum efficiency measurements

“…The tandem device architecture and the corresponding layer thicknesses of the 3‐terminal devices are depicted in Figure A. All tandem solar cells studied herein consist of absorber layers comprising poly[[4,8‐bis[(2‐ethylhexyl)oxy]benzo[1,2‐ b :4,5‐ b′ ]dithiophene‐2,6‐diyl][3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]thieno[3,4‐ b ]thiophenediyl]] and [6,6]‐phenyl C 71 ‐butyric acid methyl ester (PTB7:PC 71 BM) in the bottom subcell as well as poly[2,7‐(5,5‐bis‐(3,7‐dimethyloctyl)‐5H‐dithieno[3,2‐ b :2′,3′‐ d ]pyran)‐ alt ‐4,7‐(5,6‐difluoro‐2,1,3‐benzothiadiazole)] and [6,6]‐phenyl C 61 ‐butyric acid methyl ester (PDTP‐DFBT:PC 61 ΒM) in the top subcell as reported in an earlier publication . The third intermediate contact is fabricated from conductive poly[3,4‐ethylenedioxythiophene]:poly[4‐styrenesulfonate] (c‐PEDOT:PSS) and is incorporated into the recombination zone, which is made of m‐PEDOT:PSS (modified by additional sodium polystyrene sulfonate) and zinc oxide.…”