Halide perovskite solar cells (PSCs) exhibit a unique combination of properties, including ion migration, low nonradiative recombination and low performance dependence on temperature. Because of these idiosyncrasies, it is debatable whether standard procedures for assessing photovoltaic technologies are sufficient to appropriately evaluate this technology. Here, we show a low dependence of the open-circuit voltage on the temperature of a MAPbI 3 minimodule that allows a high-throughput outdoor analysis based on the ideality factor (n ID ). Accordingly, three representative power loss tendencies obtained from I-V curves measured with standard procedures are compared with their corresponding n ID patterns under outdoor conditions. Therefore, based on the linear relationship between T 80 and the time to reach n ID =2 (T nID2 ) is demonstrate that n ID analysis could offer important complementary information with important implications for the outdoor development of this technology, providing physical insight into the recombination mechanism dominating the performance, improving the understanding of the degradation processes and device characterization.To evaluate the lifetime of a photovoltaic device, a parameter that refers to the time at which the device reaches 80% of its initial rated power (T 80 ) is commonly used as a figure of merit. T 80 depends on various factors, such as the materials and procedures used for device fabrication, cell interconnects, weather conditions, seasonal variations, installation conditions, shading and soiling effects, and electrical mismatch between cells 1 . This parameter is commonly obtained from the relationship between the maximum power and time in a long-term analysis of a device under real outdoor operating conditions. Moreover, considering that the performance over time shows seasonal behavior and a 2 gradual performance loss tendency, T 80 has been commonly fitted using statistical methods, such as linear regression, to estimate the degradation rate 2 . However, in the case of emerging technologies such as perovskite solar cells (PSCs), most stability studies have focused on small, laboratory-scale devices operating indoors, and few statistical data have been collected under real outdoor operation 3 . Nevertheless, under high-irradiance conditions, PSCs demonstrate significant differences from conventional Si cells, as has been shown for perovskite minimodules operating outdoors 4 and for nonencapsulated solar cells under simulated weather conditions in the laboratory 5 . These results indicate that PSCs show lower correlations of their performance and open-circuit voltage (V oc ) with temperature than other commercial technologies, such as silicon 6 , for which the deleterious effects of temperature on performance are well known 7,8 . This difference in temperature sensitivity is an important aspect of PSC technology.PSCs are expected to have a significant impact in the future if they are able to provide significant performance outdoors. Outdoor conditions are highly demand...

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Abstract:With the aim to determine the photo-generated current, diode saturation current, ideality factor, shunt, and series resistances related to the one-diode model for p-i-n planar perovskite solar cells, reference cells with active area of approximately 1 cm 2 and efficiencies ranging between 4.6 and 12.2% were fabricated and characterized at standard test conditions. To estimated feasible parameters, the mean square error between the I-V curve data of these cells and the circuital model results were minimized using a Genetic Algorithm combined with the Nelder-Mead method. When considering the optimization process solutions, a numerical sensitivity analysis of the error as a function of the estimated parameters was carried out. Based on the errors behavior that is showed graphically through maps, it was demonstrated that the set of parameters estimated for each cell were reliable, meaningful, and realistic, and being related to errors lower than 9.1 × 10 −9 . Therefore, these results can be considered as global solutions of the optimization process. Moreover, based on the lower errors obtained from the optimization process, it was possible to affirm that the one-diode model is suitable to model the I-V curve of perovskite solar cells. Finally, the estimated parameters suggested that the average ideality factor is close to 2 when the fill factor of the I-V curves is higher than 0.5. Lower fill factors corresponded to ideality that was higher than 3, linked to lower efficiencies, and high loses effects reflected on lower shunt resistances. Lower ideality factor of 1.4 corresponds to the best performing solar cells.

Ag eneral and straightforwardw ay of preparingf ew-nanometer-sized well-separated MAPbI x Br 3Àx (MA = methylammonium) perovskite photosensitizers on the surface of an approximately 1 mmt hick mesoporous TiO 2 photoanode was suggested through at wo-step sequential deposition of low-concentrated lead halides( 0.10-0.30 m PbI 2 or PbBr 2 )a nd methylammonium iodide/bromide (MAI/MABr). When those nanoscale MAP-bI x Br 3Àx perovskites were incorporated asap hotosensitizer in typical solid-stated ye-sensitized solar cells (ss-DSSCs), it could be verified clearly by the capacitance analysis that nano-particulate MAPbI 3 perovskites play the same role as that of at ypical dye sensitizer (MK-2 molecule) althought heir size, composition, and structure are different.[a] Dr.Scheme1.(a-c) As implified diagram showing at wo-step deposition for preparing nanoscale MAPbI x Br 3Àx ,and (d) af ull cell structure after incorporating Spiro-OMeTAD as ah ole-transporting layer and gold as ac ounter electrode, respectively.

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