A new
organic small-molecule family comprising tetracyanoquinodimethane-substituted
quinoidal dithioalky(SR)terthiophenes (DSTQs) (DSTQ-6 (1); SR = SC6H13, DSTQ-10 (2); SR = SC10H21, DSTQ-14 (3); SR = SC10H21) was synthesized and contrasted with a nonthioalkylated
analogue (DRTQ-14 (4); R = C14H29). The physical, electrochemical, and electrical properties
of these new compounds are thoroughly investigated. Optimized geometries
obtained from density functional theory calculations and single-crystal
X-ray diffraction reveal the planarity of the SR-containing DSTQ core. DSTQs pack in a slipped π–π
stacked two-dimensional arrangement, with a short intermolecular stacking distance
of 3.55 Å and short intermolecular S···N contacts
of 3.56 Å. Thin-film morphological analysis by grazing incident
X-ray diffraction reveals that all DSTQ molecules are
packed in an edge-on fashion on the substrate. The favorable molecular
packing, the high core planarity, and very low lowest unoccupied molecular
orbital (LUMO) energy level (−4.2 eV) suggest that DSTQs could be electron-transporting semiconductors. Organic field-effect
transistors based on solution-sheared DSTQ-14 exhibit
the highest electron mobility of 0.77 cm2 V–1 s–1 with good ambient stability, which is the
highest value reported to date for such a solution process terthiophene-based
small molecular semiconductor. These results demonstrate that the
device performance of solution-sheared DSTQs can be improved
by side chain engineering.
Fine tuning of blend morphology is a key factor that limits the performance of the bulk‐heterojunction organic photovoltaics (BHJ‐OPVs). Herein, the morphological control of the binary (PM6:Y7) and ternary (PM6:Y7:PC70BM) blends is conducted through 1‐chloronaphthalene (CN) solvent additive and thermal annealing (TA) treatment with respect to their influence on the photovoltaic performance. Moreover, a distinct study is accomplished on the optical and electronic properties of the treated and nontreated binary and ternary devices by external quantum efficiency measurements and impedance spectroscopy. The results indicate that these treatments affect the performance of the binary and ternary OPVs differently. Regarding the 2% CN addition, the current density of the binary devices is improved by ≈27%, whereas the fill factor of the ternary devices shows a pronounced increment of ≈22%. A contradictory behavior is exhibited by TA for the binary and ternary OPVs. The PCEs for binary devices (with/without CN) and 2% CN‐treated ternary ones are improved, while diminishing the PCEs of the ternary ones with 0% CN. Accordingly, the highest efficiencies of the binary and ternary OPVs are obtained due to the dual effect of 2% CN solvent additive along with the TA treatments.
Fluorinated zinc and copper metallophthalocyanines MPcF 48 are synthesized and incorporated as third component small molecules in ternary organic solar cells (TOSCs). To enable the high performance of TOSCs, maximizing short-circuit current density (J SC ) is crucial. Ternary bulk heterojunction blends, consisting of a polymer donor PTB7-Th, fullerene acceptors PC 70 BM, and a third component MPcF 48 , are formulated to fabricate TOSCs with a device architecture of ITO/PFN/active layer/V 2 O 5 /Ag. Employing copper as metal atom substitution in the third component of TOSCs enhances J SC as a result of complementary absorption spectra in the near-infrared region. In combination with J SC enhancement, suppressed charge recombination, improved exciton dissociation and charge carrier collection efficiency, and better morphology lead to a slightly improved fill factor (FF), resulting in a 7% enhancement of PCE than those of binary OSCs. In addition to the increased PCE, the photostability of TOSCs has also been improved by the appropriate addition of CuPcF 48 . Detailed studies imply that metal atom substitution in phthalocyanines is an effective way to improve J SC , FF, and thus the performance and photostability of TOSCs.
Combined impedance spectroscopy and photovoltage/photocurrent transient techniques with dark J–V modelling was employed to study the shelf ISOS-D1 stability of organic solar cells.
Two tetrathioalkyl-substituted bithiophene-based small molecule quinoids (TSBTQs) having different chain lengths (thio– hexyl and –decyl) are synthesized and applied as an n-type active component in organic field effect transistors (OFETs)....
Indonesia is located along the equator lines with the high intensity of solar radiation averaging about 4.5 kWh of electrical energy/day. This potential leads to the selfsustaining energy possibility fulfilling the electricity needs. Due to their unique electronic structures and high-cost merit over the existing commercial PV technologies, perovskite solar cells (PSCs) have emerged as the next-generation photovoltaic candidate. Their highest power efficiency can be achieved of up to 22.1% in the last 5-6 years. However, this high efficiency came from CH3NH3PbI3 materials which contain lead, a toxic material. Herein calcium titanate (CT) as a lead-free perovskite material were synthesized through sintering of calcium carbonate (CaCO3) and titanium oxide (TiO2) by the sol-gel method. CT powders were characterized by SEM, XRF, FTIR and XRD then applied it onto the mesoporous heterojunction PSCs, with a device architecture ITO/TiO2/CaTiO3/C/ITO. By manipulating the raw material stoichiometry and heating temperature in the synthesis of CaTiO3, the device shows the highest power conversion efficiency (PCE) of 2.12%, shortcircuit current density (JSC) of 0.027 mA cm-2, open circuit voltage (VOC) of 0.212 V and fill factor (FF) of 53.90%. This sample can be an alternative way to create lead-free, largescale, and low-cost perovskite solar cells.
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