A polymer solar-cell based on a bulk hetereojunction design with an internal quantum efficiency of over 90% across the visible spectrum (425 nm to 575 nm) is reported. The device exhibits a power-conversion efficiency of 6% under standard air-mass 1.5 global illumination tests.

Bulk heterojunction solar cells with internal quantum efficiency approaching 100

-phenylenevinylene)s L4. Fluorene-Based Conjugated Polymers L4.1. Fluorene-Based Copolymers ContainingElectron-Rich MoietiesM4.2. Fluorene-Based Copolymers ContainingElectron-Deﬁcient MoietiesN4.3. Fluorene-Based Copolymers ContainingPhosphorescent ComplexesQ5. Carbazole-Based Conjugated Polymers R5.1. Poly(2,7-carbazole)-Based Polymers R5.2. Indolo[3,2-

https://ir.nctu.edu.tw:443/bitstream/11536/6508/1/000271856900020.pdf

Synthesis of Conjugated Polymers for Organic Solar Cell Applications

Aggregation-induced emission: phenomenon, mechanism and applications.

Solution-processed bulk-heterojunction solar cells have gained serious attention during the last few years and are becoming established as one of the future photovoltaic technologies for low-cost power production. This article reviews the highlights of the last few years, and summarizes today's state-of-the-art performance. An outlook is given on relevant future materials and technologies that have the potential to guide this young photovoltaic technology towards the magic 10% regime. A cost model supplements the technical discussions, with practical aspects any photovoltaic technology needs to fulfil, and answers to the question as to whether low module costs can compensate lower lifetimes and performances.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.200801283

Polymer‐Fullerene Bulk‐Heterojunction Solar Cells

About Supramolecular Assemblies of π-Conjugated Systems

On the basis of theoretical models and calculations, several alternating polymeric structures have been investigated to develop optimized poly(2,7-carbazole) derivatives for solar cell applications. Selected low band gap alternating copolymers have been obtained via a Suzuki coupling reaction. A good correlation between DFT theoretical calculations performed on model compounds and the experimental HOMO, LUMO, and band gap energies of the corresponding polymers has been obtained. This study reveals that the alternating copolymer HOMO energy level is mainly fixed by the carbazole moiety, whereas the LUMO energy level is mainly related to the nature of the electron-withdrawing comonomer. However, solar cell performances are not solely driven by the energy levels of the materials. Clearly, the molecular weight and the overall organization of the polymers are other important key parameters to consider when developing new polymers for solar cells. Preliminary measurements have revealed hole mobilities of about ...

Toward a rational design of poly(2,7-carbazole) derivatives for solar cells.

The ground and excited states of covalently linked fluorene-based dimers were investigated by theoretical methods and by UV−vis and fluorescence spectroscopies. The optimized structures and the cha...

Theoretical and Experimental Investigations of the Spectroscopic and Photophysical Properties of Fluorene-Phenylene and Fluorene-Thiophene Derivatives: Precursors of Light-Emitting Polymers

Fluorescence lifetimes (τ F ) of 2-[p-(dimethylamino)phenyl]-3,3-dimethyl-3H-indole (1) have been extensively studied in a two-component mixture of p-dioxane/water and also in a three-component mixture of n-heptane/AOT (sodium bis(2-ethylhexyl) sulfosuccinate)/water We have applied the concept of «dielectric enrichment» to solute/mixed solvents systems in order to evaluate the effective dielectric constants at the AOT interfaces in n-heptane We have shown that the effective dielectric constant (D) at the interface increases from 23 (water molar ratio W=O) to approximately 90 before reaching a plateau at Wœ512

Polarity of AOT micellar interfaces : use of the preferential solvation concepts in the evaluation of the effective dielectric constants

A combined theoretical and experimental study of the structure, optical, and photophysical properties of four 2,7-carbazolenevinylene-based derivatives in solution is presented. Geometry optimizations of the ground states of PCP, PCP-CN, TCT, and TCT-CN were carried out using the density functional theory (DFT/B3LYP/6-31G*). It is found that PCP and TCT are nearly planar in their ground electronic states (S0), whereas the cyano derivatives are more twisted. The nature and the energy of the first singlet−singlet electronic transitions have been obtained from time-dependent density functional theory (TDDFT) calculations performed on the optimized geometries. For all the compounds, excitation to the S1 state corresponds mainly to the promotion of one electron from the highest-occupied molecular orbital to the lowest-unoccupied molecular orbital, and the S1 ← S0 electronic transition is strongly allowed and polarized along the long axis of the molecular frame. The optimization (relaxation) of the first single...

A Theoretical, Spectroscopic, and Photophysical Study of 2,7-Carbazolenevinylene-Based Conjugated Derivatives

The thermochromic and solvatochromic properties of a series of fluorene-based conjugated polymers have been investigated. Both poly(2,7-(9,9-dioctylfluorene)) and poly(2,5-(thiophene)-alt-2,7-(9,9-dioctylfluorene)) have revealed interesting chromic properties which, on the basis of theoretical calculations, seem to be related to a relatively flexible backbone. On the other hand, the sterically hindered, nonplanar poly(2,5-(3,4-dimethylthiophene)-alt-2,7-(9,9-dioctylfluorene)) does not exhibit any significant solvatochromic and thermochromic properties which could be explained by an important energy barrier against planarity. Finally, investigations on poly(2,5-(3,4-ethylenedioxythiophene)-alt-2,7-(9,9-dioctylfluorene)) have revealed a highly conjugated conformational structure which is not significantly modified upon temperature or solvent changes.

Michel Belletête

Papers

Toward a rational design of poly(2,7-carbazole) derivatives for solar cells.

Theoretical and Experimental Investigations of the Spectroscopic and Photophysical Properties of Fluorene-Phenylene and Fluorene-Thiophene Derivatives: Precursors of Light-Emitting Polymers

Polarity of AOT micellar interfaces : use of the preferential solvation concepts in the evaluation of the effective dielectric constants

A Theoretical, Spectroscopic, and Photophysical Study of 2,7-Carbazolenevinylene-Based Conjugated Derivatives

Molecular Design and Characterization of Chromic Polyfluorene Derivatives