Lead halide–templated crystallization of methylamine-free perovskite for efficient photovoltaic modules

Science ◽  
2021 ◽  
Vol 372 (6548) ◽  
pp. 1327-1332
Author(s):  
Tongle Bu ◽  
Jing Li ◽  
Hengyi Li ◽  
Congcong Tian ◽  
Jie Su ◽  
...  

Upscaling efficient and stable perovskite layers is one of the most challenging issues in the commercialization of perovskite solar cells. Here, a lead halide–templated crystallization strategy is developed for printing formamidinium (FA)–cesium (Cs) lead triiodide perovskite films. High-quality large-area films are achieved through controlled nucleation and growth of a lead halide•N-methyl-2-pyrrolidone adduct that can react in situ with embedded FAI/CsI to directly form α-phase perovskite, sidestepping the phase transformation from δ-phase. A nonencapsulated device with 23% efficiency and excellent long-term thermal stability (at 85°C) in ambient air (~80% efficiency retention after 500 hours) is achieved with further addition of potassium hexafluorophosphate. The slot die–printed minimodules achieve champion efficiencies of 20.42% (certified efficiency 19.3%) and 19.54% with an active area of 17.1 and 65.0 square centimeters, respectively.

2019 ◽  
Author(s):  
Mohammad Rahmati ◽  
Majid Pahlevani ◽  
Gregory Welch

<p>Flexible red OLEDs based on a quadruple layer stack in-between electrodes with 160 mm<sup>2</sup> active area were fabricated in ambient air on PET via slot-die coating. For the OLED structure PET/ITO/PEDOT:PSS/PVK/PFO:tPDI<sub>2</sub>N-EH/ZnO/Ag the ink formulations and coating parameters for each layer were systematically evaluated and optimized. The air-stable red-light emitting material tPDI<sub>2</sub>N-EH was successfully utilized as blended homogeneous film with PFO for the emitting layer. The use of an organic hole-transport layer (PVK) and inorganic electron injection layer (ZnO) significantly improved the brightness of the reference device from 4 cd/m<sup>2</sup> to 303 cd/m<sup>2</sup>. Surface analysis using AFM measurements showed that PVK interlayer reduced the surface roughness of the hole injection layer (PEDT:PSS) from 0.45 nm to 0.17 nm, which improved the ability to form uniform emitting layers on top. In addition, the ZnO interlayer improved the average roughness of the device from 1.26 nm to 0.85 nm and reduced the turn-on voltage of the device from 5.0 V to 2.8 V.</p>


2019 ◽  
Author(s):  
Mohammad Rahmati ◽  
Majid Pahlevani ◽  
Gregory Welch

<p>Flexible red OLEDs based on a quadruple layer stack in-between electrodes with 160 mm<sup>2</sup> active area were fabricated in ambient air on PET via slot-die coating. For the OLED structure PET/ITO/PEDOT:PSS/PVK/PFO:tPDI<sub>2</sub>N-EH/ZnO/Ag the ink formulations and coating parameters for each layer were systematically evaluated and optimized. The air-stable red-light emitting material tPDI<sub>2</sub>N-EH was successfully utilized as blended homogeneous film with PFO for the emitting layer. The use of an organic hole-transport layer (PVK) and inorganic electron injection layer (ZnO) significantly improved the brightness of the reference device from 4 cd/m<sup>2</sup> to 303 cd/m<sup>2</sup>. Surface analysis using AFM measurements showed that PVK interlayer reduced the surface roughness of the hole injection layer (PEDT:PSS) from 0.45 nm to 0.17 nm, which improved the ability to form uniform emitting layers on top. In addition, the ZnO interlayer improved the average roughness of the device from 1.26 nm to 0.85 nm and reduced the turn-on voltage of the device from 5.0 V to 2.8 V.</p>


2020 ◽  
Vol 10 (37) ◽  
pp. 2001567 ◽  
Author(s):  
Shih‐Han Huang ◽  
Cheng‐Kang Guan ◽  
Pei‐Huan Lee ◽  
Hung‐Che Huang ◽  
Chia‐Feng Li ◽  
...  

2016 ◽  
Vol 113 (28) ◽  
pp. 7717-7721 ◽  
Author(s):  
G. P. Nagabhushana ◽  
Radha Shivaramaiah ◽  
Alexandra Navrotsky

Hybrid perovskites, especially methylammonium lead iodide (MAPbI3), exhibit excellent solar power conversion efficiencies. However, their application is plagued by poor chemical and structural stability. Using direct calorimetric measurement of heats of formation, MAPbI3 is shown to be thermodynamically unstable with respect to decomposition to lead iodide and methylammonium iodide, even in the absence of ambient air or light or heat-induced defects, thus limiting its long-term use in devices. The formation enthalpy from binary halide components becomes less favorable in the order MAPbCl3, MAPbBr3, MAPbI3, with only the chloride having a negative heat of formation. Optimizing the geometric match of constituents as measured by the Goldschmidt tolerance factor provides a potentially quantifiable thermodynamic guide for seeking chemical substitutions to enhance stability.


2021 ◽  
Vol 21 (19) ◽  
pp. 15153-15170
Author(s):  
Hélène Angot ◽  
Connor Davel ◽  
Christine Wiedinmyer ◽  
Gabrielle Pétron ◽  
Jashan Chopra ◽  
...  

Abstract. Atmospheric non-methane hydrocarbons (NMHCs) play an important role in the formation of secondary organic aerosols and ozone. After a multidecadal global decline in atmospheric mole fractions of ethane and propane – the most abundant atmospheric NMHCs – previous work has shown a reversal of this trend with increasing atmospheric abundances from 2009 to 2015 in the Northern Hemisphere. These concentration increases were attributed to the unprecedented growth in oil and natural gas (O&amp;NG) production in North America. Here, we supplement this trend analysis building on the long-term (2008–2010; 2012–2020) high-resolution (∼3 h) record of ambient air C2–C7 NMHCs from in situ measurements at the Greenland Environmental Observatory at Summit station (GEOSummit, 72.58 ∘ N, 38.48 ∘ W; 3210 m above sea level). We confirm previous findings that the ethane mole fraction significantly increased by +69.0 [+47.4, +73.2; 95 % confidence interval] ppt yr−1 from January 2010 to December 2014. Subsequent measurements, however, reveal a significant decrease by −58.4 [−64.1, −48.9] ppt yr−1 from January 2015 to December 2018. A similar reversal is found for propane. The upturn observed after 2019 suggests, however, that the pause in the growth of atmospheric ethane and propane might only have been temporary. Discrete samples collected at other northern hemispheric baseline sites under the umbrella of the NOAA cooperative global air sampling network show a similar decrease in 2015–2018 and suggest a hemispheric pattern. Here, we further discuss the potential contribution of biomass burning and O&amp;NG emissions (the main sources of ethane and propane) and conclude that O&amp;NG activities likely played a role in these recent changes. This study highlights the crucial need for better constrained emission inventories.


Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 915 ◽  
Author(s):  
Lei Shi ◽  
Huiying Hao ◽  
Jingjing Dong ◽  
Tingting Zhong ◽  
Chen Zhang ◽  
...  

Intermediate phase is considered an important aspect to deeply understand the crystallization procedure in the growth of high-quality perovskite layers by an anti-solvent technique. However, the moisture influence on the intermediate phase formation is not clear in air conditions as yet. In this work, pure (FA0.2MA1.8)Pb3X8(DMSO·DMF) intermediate phase was obtained in as-prepared perovskite film by spin-coating the precursor of co-solvent (DMSO and DMF) in an ambient air (RH20–30%). Moreover, the appropriate quantity of ethyl acetate (C4H8O2, EA) also controls the formation of pure intermediate phase. The uniform and homogeneous perovskite film was obtained after annealing this intermediate film. Therefore, the best power conversion efficiency (PCE) of perovskite solar cells (PSCs) is 16.24% with an average PCE of 15.53%, of which almost 86% of its initial PCE was preserved after 30 days in air conditions. Besides, the steady-state output efficiency ups to 15.38% under continuous illumination. In addition, the PCE of large area device (100 mm2) reaches 11.11% with a little hysteresis effect. This work would give an orientation for PSCs production at the commercial level, which could lower the cost of fabricating the high efficiency PSCs.


2018 ◽  
Vol 11 (12) ◽  
pp. 3358-3366 ◽  
Author(s):  
Tianqi Niu ◽  
Jing Lu ◽  
Ming-Chun Tang ◽  
Dounya Barrit ◽  
Detlef-M. Smilgies ◽  
...  

We report a Ruddlesden–Popper/3D heterostructure combined with molecule passivation within α-phase FAPbI3 films for high-performance and ambient-air-stable solar cells.


Science ◽  
2020 ◽  
Vol 370 (6512) ◽  
pp. 108-112 ◽  
Author(s):  
Gwisu Kim ◽  
Hanul Min ◽  
Kyoung Su Lee ◽  
Do Yoon Lee ◽  
So Me Yoon ◽  
...  

High-efficiency lead halide perovskite solar cells (PSCs) have been fabricated with α-phase formamidinium lead iodide (FAPbI3) stabilized with multiple cations. The alloyed cations greatly affect the bandgap, carrier dynamics, and stability, as well as lattice strain that creates unwanted carrier trap sites. We substituted cesium (Cs) and methylenediammonium (MDA) cations in FA sites of FAPbI3 and found that 0.03 mol fraction of both MDA and Cs cations lowered lattice strain, which increased carrier lifetime and reduced Urbach energy and defect concentration. The best-performing PSC exhibited power conversion efficiency >25% under 100 milliwatt per square centimeter AM 1.5G illumination (24.4% certified efficiency). Unencapsulated devices maintained >80% of their initial efficiency after 1300 hours in the dark at 85°C.


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