Organic Bulk‐Heterojunction Photovoltaics Based on Alkyl Substituted Discotics

Li, Jiaoli; Kastler, Marcel; Pisula, Wojciech; Robertson, Joseph W. F.; Wasserfallen, Daniel; Grimsdale, Andrew C.; Wu, Jishan; Müllen, Kläus

doi:10.1002/adfm.200600679

Cited by 78 publications

(44 citation statements)

References 35 publications

(6 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The length of the insulating side-chains can play also an important role, aside from the morphology, since the ability to absorb light decreases with longer alkyl chains. [58] Furthermore, shorter sidechains induce higher crystallinity and a more pronounced separation between the different phases. Finally, as mentioned above, longer side-chains increase the insulating effect on the 1D charge carrier transport in the discotic systems and, thus, hinder an efficient exciton polarization and separation.…”

Section: à4mentioning

confidence: 99%

Liquid Crystalline Ordering and Charge Transport in Semiconducting Materials

Pisula¹,

Zorn²,

Chang³

et al. 2009

Macromol. Rapid Commun.

371

276

View full text Add to dashboard Cite

Organic semiconducting materials offer the advantage of solution processability into flexible films. In most cases, their drawback is based on their low charge carrier mobility, which is directly related to the packing of the molecules both on local (amorphous versus crystalline) and on macroscopic (grain boundaries) length scales. Liquid crystalline ordering offers the possibility of circumventing this problem. An advanced concept comprises: i) the application of materials with different liquid crystalline phases, ii) the orientation of a low viscosity high temperature phase, and, iii) the transfer of the macroscopic orientation during cooling to a highly ordered (at best, crystalline-like) phase at room temperature. At the same time, the desired orientation for the application (OLED or field-effect transistor) can be obtained. This review presents the use of molecules with discotic, calamitic and sanidic phases and discusses the sensitivity of the phases with regard to defects depending on the dimensionality of the ordered structure (columns: 1D, smectic layers and sanidic phases: 2D). It presents ways to systematically improve charge carrier mobility by proper variation of the electronic and steric (packing) structure of the constituting molecules and to reach charge carrier mobilities that are close to and comparable to amorphous silicon, with values of 0.1 to 0.7 cm(2) · V(-1) · s(-1) . In this context, the significance of cross-linking to stabilize the orientation and liquid crystalline behavior of inorganic/organic hybrids is also discussed.

show abstract

Section: à4mentioning

confidence: 99%

Liquid Crystalline Ordering and Charge Transport in Semiconducting Materials

Pisula¹,

Zorn²,

Chang³

et al. 2009

Macromol. Rapid Commun.

371

276

View full text Add to dashboard Cite

show abstract

“…Swallow-tailed hexabenzocoronenes have also been used for OPVs. [ 66 ] Recently we introduced a liquid crystal composite approach to provide a distributed interface to vertically separate electrondonating and electron-accepting fi lms in an OPV device. [ 67 , 68 ] The concept is illustrated in Figure 5 a .…”

Section: Organic Photovoltaicsmentioning

confidence: 99%

Ordered Materials for Organic Electronics and Photonics

2010

View full text Add to dashboard Cite

We present a critical review of semiconducting/light emitting, liquid crystalline materials and their use in electronic and photonic devices such as transistors, photovoltaics, OLEDs and lasers. We report that annealing from the mesophase improves the order and packing of organic semiconductors to produce state-of-the-art transistors. We discuss theoretical models which predict how charge transport and light emission is affected by the liquid crystalline phase. Organic photovoltaics and OLEDs require optimization of both charge transport and optical properties and we identify the various trade-offs involved for ordered materials. We report the crosslinking of reactive mesogens to give pixellated full-colour OLEDs and distributed bi-layer photovoltaics. We show how the molecular organization inherent to the mesophase can control the polarization of light-emitting devices and the gain in organic, thin-film lasers and can also provide distributed feedback in chiral nematic mirrorless lasers. We update progress on the surface alignment of liquid crystalline semiconductors to obtain monodomain devices without defects or devices with spatially varying properties. Finally the significance of all of these developments is assessed.

show abstract

“…On the contrary, their high crystallinity could be exploited when this ethylpropyl-substituted PBI was blended with discotic liquid crystal alkylated hexabenzocoronene (HBC) (Fig. 5) [26,33,34]. An external quantum efficiency (EQE) of 34% corresponding to about 2% PCE was observed for the PBI/HBC blend under illumination at 490 nm.…”

Section: Non-fullerenes Acceptors For Organic Solar Cellsmentioning

confidence: 99%

An overview of molecular acceptors for organic solar cells

Hudhomme

2013

EPJ Photovolt.

View full text Add to dashboard Cite

Organic solar cells (OSCs) have gained serious attention during the last decade and are now considered as one of the future photovoltaic technologies for low-cost power production. The first dream of attaining 10% of power coefficient efficiency has now become a reality thanks to the development of new materials and an impressive work achieved to understand, control and optimize structure and morphology of the device. But most of the effort devoted to the development of new materials concerned the optimization of the donor material, with less attention for acceptors which to date remain dominated by fullerenes and their derivatives. This short review presents the progress in the use of non-fullerene small molecules and fullerene-based acceptors with the aim of evaluating the challenge for the next generation of acceptors in organic photovoltaics.

show abstract

Organic Bulk‐Heterojunction Photovoltaics Based on Alkyl Substituted Discotics

Cited by 78 publications

References 35 publications

Liquid Crystalline Ordering and Charge Transport in Semiconducting Materials

Liquid Crystalline Ordering and Charge Transport in Semiconducting Materials

Ordered Materials for Organic Electronics and Photonics

An overview of molecular acceptors for organic solar cells

Contact Info

Product

Resources

About