2015 Bui - RSC Adv (original) (raw)
Related papers
RSC Adv., 2015
Three tris(thienylphenyl)amine-based molecular glass hole transporting materials were synthetized, characterized and incorporated in solid state dye-sensitized solar cells. Devices using these compounds as solid hole conductors show relatively high V oc thanks to good energy level matching between them and the associated D102 indoline dye. However, they yield relatively low J sc and FF compared to Spiro-OMeTAD based control devices, which is due to an order of magnitude lower conductivity with respect to Spiro-OMeTAD. Maximum solar-to-electrical energy conversion efficiencies of 1.2% under standard illumination condition was obtained. Stability tests of unsealed devices in air under continuous illumination have been performed and devices based on new compounds have kept up to 80% of their initial efficiency.
Advanced Energy Materials, 2014
suffer from potential leakage problems associated with the volatile nature of the liquid electrolyte, limiting this technology for large-scale applications. [ 3 ] In an effort to address these issues, a p-type organic semiconductor termed 2,2′,7,7′-tetrakis-(N,N-dip -methoxyphenyl-amine)9,9′ spirobifl uorene (Spiro-OMeTAD) was developed to replace the liquid electrolyte as a redox couple in the fabrication of "solid-state" dye-sensitized solar cells (ssDSCs) by Bach et al. in 1998. [ 4 ] To date, the highest effi ciency of 7.2% for ssDSCs have been achieved using Spiro-OMeTAD as the hole transport material (HTM), which was reported by Nazeeruddin and co-workers. [ 5 ] Recently, Snaith and co-workers employed an organometallic halide perovskite with Spiro-OMeTAD as HTM obtained a record effi ciency of 15.4%. [ 6 ] However, previous studies have demonstrated that the low hole mobility and conductivity of Spiro-OMeTAD signifi cantly limits the device performance near the maximum power point in solar cell. [ 7,8 ] In addition, the lengthy synthetic route of Spiro-OMeTAD may make it impractical for large-scale application in ssDSCs. [ 9 ] More importantly, the substantial overpotential required for dye A series of triphenylamine-based small molecule organic hole transport materials (HTMs) with low crystallinity and high hole mobility are systematically investigated in solid-state dye-sensitized solar cells (ssDSCs). By using the organic dye LEG4 as a photosensitizer, devices with X3 and X35 as the HTMs exhibit desirable power conversion effi ciencies (PCEs) of 5.8% and 5.5%, respectively. These values are slightly higher than the PCE of 5.4% obtained by using the state-of-the-art HTM Spiro-OMeTAD. Meanwhile, transient photovoltage decay measurement is used to gain insight into the complex infl uences of the HTMs on the performance of devices. The results demonstrate that smaller HTMs induce faster electron recombination in the devices and suggest that the size of a HTM plays a crucial role in device performance, which is reported for the fi rst time.
ACS Nano, 2012
We present the synthesis and device characterization of new hole transport materials (HTMs) for application in solid-state dye-sensitized solar cells (ssDSSCs). In addition to possessing electrical properties well suited for ssDSSCs, these new HTMs have low glass transition temperatures, low melting points, and high solubility, which make them promising candidates for increased pore filling into mesoporous titania films. Using standard device fabrication methods and Z907 as the sensitizing dye, power conversion efficiencies (PCE) of 2.94% in 2-μm-thick cells were achieved, rivaling the PCE obtained by control devices using the state-ofthe-art HTM spiro-OMeTAD. In 6-μm-thick cells, the device performance is shown to be higher than that obtained using spiro-OMeTAD, making these new HTMs promising for preparing high-efficiency ssDSSCs.
Dye-sensitized Solar Cells: New Approaches with Organic Solid-state Hole Conductors
CHIMIA, 2015
Solid-state dye-sensitized solar cells (sDSCs) in which a solid organic charge-transfer medium, or hole conductor (HC), is interposed between a dye-coated mesoporous oxide electrode and a conductive counter electrode, have attracted considerable interest as viable alternatives to the more ubiquitous mediator-electrolyte DSC. Of particular importance to efficient operation are, in addition to the useful processes contributing to current generation (light harvesting, electron injection and current collection), the recombinative deleterious processes. The organic HCs are highly reactive toward electrons in the oxide or the conducting glass support, therefore necessitating the inclusion of a carefully prepared thin blocking oxide underlayer support as well as the molecular design of special dark current-suppressing dyes. Initially (mid-1990s) sDSCs with organic small molecular weight hole conductors have undergone systematic investigation. At the same time the first tests of sDSCs with ...
ChemNanoMat, 2015
Three 3,6-di(4-methoxyphenyl)amino N-alkylated carbazoles were synthesized, characterized and incorporated in solid state dye-sensitized solar cells. Devices using these compounds as solid hole conductors showed relative high V oc thanks to good energy level matching between them and D102 dye. However, they yield relatively low J sc and FF compared to spiro-OMeTAD-based control devices, which is due to an order of magnitude lower mobility and conductivity with respect to spiro-OMeTAD. Maximum PCEs for Nethyl and N-hexyl 3,6-di(4-methoxyphenyl)amino carbazoles (2 a, 2 b) are 1.6 %, and 1.8 % respectively, whereas spiro-OMeTAD devices gave 4.4 %. Stability tests in air under continuous illumination have been reported.
Journal of Materials Chemistry a, 2013
We have synthesized and characterized a series of triphenylamine-based hole-transport materials (HTMs), and studied their function in solid-state dye sensitized solar cells (ss-DSSCs). By increasing the electron-donating strength of functional groups (-H <-Me <-SMe <-OMe) we have systematically shifted the oxidation potential and ensuing photocurrent generation and open-circuit voltage of the solar cells. Correlating the electronic properties of the HTM to the device operation highlights a significant energy offset required between the Dye-HTM highest occupied molecular orbital (HOMO) energy levels. From this study, it is apparent that precise control and tuning of the oxidation potential is a necessity, and usually not achieved with most HTMs developed to date for ss-DSSCs. To significantly increase the efficiency of solid-state DSSCs understanding these properties, and implementing dye-HTM combinations to minimize the required HOMO offset is of central importance.
Synthetic Metals
All solid-state dye-sensitized solar cells (ss-DSSCs) based on the reference D102 organic dye and using poly(3-hexylthiophene) (P3HT) as hole transporting material were fabricated and compared to the most used 2,2 0 ,7,7 0-tetrakis-(N,N-dip -methoxyphenylamine)-9,9 0-spirobifluorene (spiro-OMeTAD). Power conversion efficiency of 4.78% was reached with P3HT vs. 3.99% with spiro-OMeTAD, which emphasizes that polythiophene derivatives remain serious alternatives to spiro-OMeTAD for efficient and low-cost photovoltaic energy conversion. Here, P3HT combining high regioregularity, medium-range molecular weight and narrow dispersity was targeted. The ability of those P3HT chains to form semicrystalline domains upon annealing leads to improved hole mobility, photocurrent collection and thus, device performance.