Electron transport layers (ETLs) with suitable energy level alignment for facilitating charge carrier transport as well as electron extraction are essential for planar heterojunction perovskite solar ...cells (PSCs) to achieve high open-circuit voltage (V OC) and short-circuit current. Herein we systematically investigate band offset between ETL and perovskite absorber by tuning F doping level in SnO2 nanocrystal. We demonstrate that gradual substitution of F– into the SnO2 ETL can effectively reduce the band offset and result in a substantial increase in device V OC. Consequently, a power conversion efficiency of 20.2% with V OC of 1.13 V can be achieved under AM 1.5 G illumination for planar heterojunction PSCs using F-doped SnO2 bilayer ETL. Our finding provides a simple pathway to tailor ETL/perovskite band offset to increase built-in electric field of planar heterojunction PSCs for maximizing V OC and charge collection simultaneously.
A high molar extinction coefficient heteroleptic ruthenium complex, incorporating an electron-rich hexylthio-terminal chain, has been synthesized and demonstrated as an efficient sensitizer for ...dye-sensitized solar cells. With this new sensitizer excellent power conversion efficiency is 11.5% and 4.7% obtained under an irradiation of full sunlight (air mass 1.5 global) in combination with a volatility electrolyte and solid state hole transporting material, respectively. The devices with low volatility electrolyte showed good stability under visible-light soaking at 60 °C during 1000 h of accelerated tests.
α‐Formamidinium lead iodide (α‐FAPbI3) is one of the most promising candidate materials for high‐efficiency and thermally stable perovskite solar cells (PSCs) owing to its outstanding optoelectrical ...properties and high thermal stability. However, achieving a stable form of α‐FAPbI3 where both the composition and the phase are pure is very challenging. Herein, we report on a combined strategy of precursor engineering and grain anchoring to successfully prepare methylammonium (MA)‐free and phase‐pure stable α‐FAPbI3 films. The incorporation of volatile FA‐based additives in the precursor solutions completely suppresses the formation of non‐perovskite δ‐FAPbI3 during film crystallization. Grains of the desired α‐phase are anchored together and stabilized when 4‐tert‐butylbenzylammonium iodide is permeated into the α‐FAPbI3 film interior via grain boundaries. This cooperative scheme leads to a significantly increased efficiency close to 21 % for FAPbI3 perovskite solar cells. Moreover, the stabilized PSCs exhibit improved thermal stability and maintained ≈90 % of their initial efficiency after storage at 50 °C for over 1600 hours.
Formamidinium (FA)‐based additives in precursor solutions suppressed the formation of the undesired δ phase during the crystallization of FAPbI3 perovskites, and heat‐induced permeation of 4‐tert‐butylbenzylammonium iodide (tBBAI) into inner perovskite grains stabilized the α structure. Solar cells assembled from this material exhibited improved power conversion efficiency and stability.
In solid‐state dye sensitized solar cells (SSDSCs) charge recombination at the dye‐hole transporting material interface plays a critical role in the cell efficiency. For the first time we report on ...the influence of dipolar co‐adsorbents on the photovoltaic performance of sensitized hetero‐junction solar cells. In the present study, we investigated the effect of two zwitterionic butyric acid derivatives differing only in the polar moiety attached to their common 4 carbon‐chain acid, i.e., 4‐guanidinobutyric acid (GBA) and 4‐aminobutyric acid (ABA). These two molecules were implemented as co‐adsorbents in conjunction with Z907Na dye on the SSDSC. It was found that a Z907Na/GBA dye/co‐adsorbent combination increases both the open circuit voltage (Voc) and short‐circuit current density (Jsc) as compared to using Z907Na dye alone. The Z907Na/ABA dye/co‐adsorbent combination increases the Jsc. Impedance and transient photovoltage investigations elucidate the cause of these remarkable observations.
Charge recombination at the dye‐hole transporting material interface plays a critical role in the cell efficiency in solid‐state dye sensitized solar cells. In this study influence from the zwitterionic co‐adsorbents (4‐guanidinobutyric Acid (GBA) and 4‐aminobutyric Acid (ABA)) used in the solid‐state DSC is discussed. Important information on the charge recombination across the dye sensitized heterojunction is gathered in this fashion.
Infiltration of mesoporous TiO2 scaffolds by CH3NH3PbI3 is more complete when using sequential compared to single step deposition processing and avoids formation of disordered capping layers ...affording greatly improved performance of perovskite based photovoltaics.
TiO2 nanorod arrays were prepared on top of a transparent conductive glass substrate covered with a thin TiO2 compact layer. Solid-state dye-sensitized solar cells (SSDSCs) were fabricated using ...these structured TiO2 films sensitized with C106 dye as a photoanode and 2,2′,7,7′-tetrakis-(N,N-dipmethoxyphenylamine) 9,9′-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. Photovoltaic power conversion efficiency of 2.9% was obtained at full sunlight intensity. The electron lifetime as well as the electron diffusion coefficient in the device was determined by charge extraction, transient photovoltage decay, and open-circuit photovoltage decay experiments.
Two new 1,2,5thiadiazolo3,4-cpyridine-containing D-A-π–A organic dyes (PT-1 and PT-2) have been designed and synthesized for utilization in dye-sensitized solar cells. PT-2 sensitizer, which was ...synthesized by incorporating the 4,4-bis(2-ethylhexyl)-4H-cyclopenta1,2-b:5,4-b′dithiophene moiety as an additional π-bridge into the organic sensitizer PT-1, not only brings about significant changes in the absorption spectrum but also suppresses the charge recombination rate as compared to PT-1. Moreover, PT-2 exhibits an aesthetic blue color covering a broad spectral range into the NIR region. The incident-photon to electron-conversion efficiency of PT-2 shows an onset approaching 850 nm with power conversion efficiency of 6.7% fabricated when utilizing an iodide-based redox electrolyte. These results demonstrate that these 1,2,5thiadiazolo3,4-cpyridine-based sensitizers are quite promising candidates to use for lowering the HOMO–LUMO gap and shifting the spectral response toward the NIR.
A ruthenium sensitizer (coded C101, NaRu (4,4′‐bis(5‐hexylthiophen‐2‐yl)‐2,2′‐bipyridine) (4‐carboxylic acid‐4′‐caboxylate‐2,2′‐bipyridine) (NCS)2) containing a hexylthiophene‐conjugated bipyridyl ...group as an ancillary ligand is presented for use in solid‐state dye‐sensitized solar cells (SSDSCs). The high molar‐extinction coefficient of this dye is advantageous compared to the widely used Z907 dye, (NaRu (4‐carboxylic acid‐4′‐carboxylate) (4,4′‐dinonyl‐2,2′‐bipyridine) (NCS)2). In combination with an organic hole‐transporting material (spiro‐MeOTAD, 2,2′,7,7′‐tetrakis‐(N,N‐di‐p‐methoxyphenylamine) 9, 9′‐spirobifluorene), the C101 sensitizer exhibits an excellent power‐conversion efficiency of 4.5% under AM 1.5 solar (100 mW cm−2) irradiation in a SSDSC. From electronic‐absorption, transient‐photovoltage‐decay, and impedance measurements it is inferred that extending the π‐conjugation of spectator ligands induces an enhanced light harvesting and retards the charge recombination, thus favoring the photovoltaic performance of a SSDSC.
One of the active research fields in dye‐sensitized solar cells is in enhancing the molar‐extinction coefficient and red‐shifting the spectral response of the charge‐transfer chromophores. A ruthenium‐complex sensitizer is employed for high‐efficiency solid‐state dye‐sensitized solar cells. The heteroleptic sensitizer features hexylthiophene in its ancillary bipyridyl ligand, which extends the π‐conjugation, resulting in a conversion efficiency of 4.5% under AM 1.5 full sunlight.
The high molar extinction coefficient heteroleptic ruthenium dye, NaRu(4,4′-bis(5-(hexylthio)thiophen-2-yl)-2,2′-bipyridine) (4-carboxylic acid-4′-carboxylate-2,2′-bipyridine) (NCS)
2, exhibits ...certified 5% electric power conversion efficiency at AM 1.5 solar irradiation (100
mW
cm
−2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis-(N,N-di-pmethoxyphenylamine)-9,9′-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. This demonstration elucidates a class of photovoltaic devices with potential for low-cost power generation.
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![Thiadiazolo[3,4‑c]pyridine ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1932-7447/small "Thiadiazolo[3,4‑c]pyridine Acceptor Based Blue Sensitizers for High Efficiency Dye-Sensitized Solar Cells")
