No abstract

Poly(3-hexylthiophene) (P3HT) remains of significant importance as a prototypical benchmark hole conductor material in Organic Photovoltaics (OPVs). In this review we discuss synthetic strategies to P3HT, particularly focusing on those leading to the regioregular form and discussing key physical and morphological properties. Finally, a survey and a brief discussion of P3HT performance in bulkheterojunction (BHJ) OPVs are also provided.

Green chemistry and flow chemistry are ideal partners for accessing novel chemical spaces and define highly efficient synthetic tools.

Formic acid is a main product from biomass-derived carbohydrates and is attracting ever more attention as a hydrogen source for a sustainable chemical production.

We report the synthesis and characterization of a series of five extended arylacetylenes, 9,10-bis-{[m,p-bis(hexyloxy)phenyl]ethynyl}-anthracene (A-P6t, 1), 9,10-bis-[(p-{[m,p-bis(hexyloxy) phenyl]ethynyl}phenyl)ethynyl]-anthracene (PA-P6t, 2), 4,7-bis-{[m,p-bis(hexyloxy)phenyl]ethynyl}-2,1,3-benzothiadiazole (BTZ-P6t, 5), 4,7-bis(5-{[m,p-bis(hexyloxy)phenyl]ethynyl}thien-2-yl)-2,1,3-benzothiadiazole (TBTZ-P6t, 6), and 7,7'-({[m,p-bis(hexyloxy)phenyl]ethynyl}-2,1,3-benzothiadiazol-4,4'-ethynyl)-2,5-thiophene (BTZT-P6t, 7), and two arylvinylenes, 9,10-bis-{(E)-[m,p-bis(hexyloxy)phenyl]vinyl}-anthracene (A-P6d, 3), 9,10-bis-[(E)-(p-{(E)-[m,p-bis(hexyloxy)phenyl]vinyl}phenyl)vinyl]-anthracene (PA-P6d, 4). Trends in optical absorption spectra and electrochemical redox processes are first described. Next, the thin-film microstructures and morphologies of films deposited from solution under various conditions are investigated, and organic field-effect transistors (OFETs) and bulk heterojunction photovoltaic (OPV) cells fabricated. We find that substituting acetylenic for olefinic linkers on the molecular cores significantly enhances device performance. OFET measurements reveal that all seven of the semiconductors are FET-active and, depending on the backbone architecture, the arylacetylenes exhibit good p-type mobilities (mu up to approximately 0.1 cm(2) V(-1) s(-1)) when optimum film microstructural order is achieved. OPV cells using [6,6]-phenyl C(61)-butyric acid methyl ester (PCBM) as the electron acceptor exhibit power conversion efficiencies (PCEs) up to 1.3% under a simulated AM 1.5 solar irradiation of 100 mW/cm(2). These results demonstrate that arylacetylenes are promising hole-transport materials for p-channel OFETs and promising donors for organic solar cells applications. A direct correlation between OFET arylacetylene hole mobility and OPV performance is identified and analyzed.

The development of waste minimized and clean synthetic methodologies to afford polymeric semiconductors is essential for the successful commercialization of opto-electronic devices.

Substituting olefinic for acetylenic pi-spacers in anthracene-based conjugated semiconductor donors leads to appreciable increases in the power conversion efficiencies of the resulting bulk heterojunction solar cells.

γ-Valerolactone (GVL) is an excellent reaction medium, derived from biomasses, which can replace classic dipolar aprotic media such as DMF or NMP.