Organic photoresponse materials and devices are critically important to organic optoelectronics and energy crises. The activities of photoresponse in organic materials can be summarized in three effects, photoconductive, photovoltaic and optical memory effects. Correspondingly, devices based on the three effects can be divided into (i) photoconductive devices such as photodetectors, photoreceptors, photoswitches and phototransistors, (ii) photovoltaic devices such as organic solar cells, and (iii) optical data storage devices. It is expected that this systematic analysis of photoresponse materials and devices could be a guide for the better understanding of structure–property relationships of organic materials and provide key clues for the fabrication of high performance organic optoelectronic devices, the integration of them in circuits and the application of them in renewable green energy strategies (critical review, 452 references).

Organic photoresponse materials and devices

The first highly efficient and scalable cobalt-catalyzed directed C-H functionalization with carbene precursors is presented. This methodology provides a modular route towards a new class of conjugated polycyclic hydrocarbons with tunable emission wavelengths both in solution and in the solid state.

Cobalt(III)-Catalyzed Directed C ? H Coupling with Diazo Compounds: Straightforward Access towards Extended π-Systems

π-Conjugated small molecules, oligomers, and macromolecules are being used in the fabrication of a wide variety of organic electronic devices such as organic field-effect transistors (OFETs), organic photovoltaic (OPV) devices, and organic light-emitting diodes (OLEDs). Efficient syntheses involving fewer steps, fewer toxic reagents, and highly reactive compounds are needed to lower the cost of materials in a manner that is fundamentally more eco-friendly. Additionally, synthetic approaches for π-conjugated materials with more functional group tolerance are desirable to expand the range of properties that can be realized in such materials. Developing new synthetic routes to materials can both broaden the scope of science that can be explored and increase the probability that interesting materials can be developed in an economically viable manner for inclusion in consumer products. One such synthetic strategy that can impact all of these issues is carbon–hydrogen bond activation and subsequent carbon–carbo...

C–H Arylation Reaction: Atom Efficient and Greener Syntheses of π-Conjugated Small Molecules and Macromolecules for Organic Electronic Materials

First reported by Farnum as much as 40 years ago, diketopyrrolopyrroles (2,5-dihydropyrrolo[4,3-c]pyrrolo-1,4-diones) are currently one of the most widely used dyes, with applications that span high-quality pigments, field-effect transistors, bulk-heterojunction solar cells, dye-sensitized solar cells, and fluorescence imaging. Due to the breadth of their utility, there have been several focused reviews on this topic since 1988. Considering the growing importance of these dyes, this review describes the overall progress made in four decades in both synthesis and the elucidation of their reactivity, and offers a critical comparison of various methods reported in the literature. The relationship between their structure and optical properties is also reviewed in detail. The extension of diketopyrrolopyrroles' chromophore leads to a significant change in both linear and nonlinear optical properties. A very strong bathochromic shift in the absorption and an increase in the two-photon absorption cross-section are typical for these analogues. Straightforward synthesis combined with good stability and a near-unity fluorescence quantum yield ensures that diketopyrrolopyrroles will continue to attract attention for years to come. The goal of this review is to systematize knowledge on these dyes, enabling their use in more real-world applications.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adom.201400559

Diketopyrrolopyrroles: Synthesis, Reactivity, and Optical Properties

Sustainable metal complexes for organic light-emitting diodes (OLEDs)

Diketopyrrolopyrrole (DPP) derivatives are an important class of high-performance pigment used in inks, paints, plastics, and organic electronics. Until now, DPP derivatives containing sophisticated aryl units at the DPP core have usually been obtained via Suzuki, Stille, or Negishi cross-coupling reactions, which require organometallic precursors. In this work, a series of DPP-based π-conjugated molecules bearing diverse aryl substituents on the thiophene- or benzene-DPPs were facilely synthesized in moderate to excellent yields through the Pd-catalyzed direct arylation of C–H bonds. The synthetic procedures feature advantages over traditional C–C cross-coupling reactions such as: (1) avoidance of the use of organometallic reagents in the starting materials leading to simpler byproducts and higher atom economy, (2) fewer synthetic steps, (3) higher yields, (4) better compatibility with chemically sensitive functional groups, and (5) simpler catalytic systems free of phosphine ligands. These advantages make the present protocol an ideal and versatile strategy for the synthesis of DPP derivatives, especially for structurally complicated DPPs that may possess chemically sensitive functionalities. The optical and electrochemical properties of the synthesized DPPs (17 compounds) were systematically investigated using UV-vis spectroscopy, steady-state fluorescence spectroscopy, and cyclic voltammetry (CV).

https://www.rsc.org/suppdata/ta/c2/c2ta01318e/c2ta01318e.pdf

C–H activation: making diketopyrrolopyrrole derivatives easily accessible

Fluorinated Alq3 derivatives with tunable optical properties.

Synthesis, aggregation and photoconductive properties of alkoxycarbonyl substituted perylenes

The structural and electrical properties of n-channel OTFTs based on N,N'-(4-monofluorophenyl)-3,4,9,10-perylene tetracarboxylic diimide (D4MFPP) were investigated. The influence of surface treatment on the mobility and the interface traps were quantitatively evaluated.

Jia-Chi Huang

Papers

C–H activation: making diketopyrrolopyrrole derivatives easily accessible

Fluorinated Alq3 derivatives with tunable optical properties.

Synthesis, aggregation and photoconductive properties of alkoxycarbonyl substituted perylenes

Improvement of electrical characteristics of fluorinated perylene diimide thin-film transistors by gate dielectric surface treatment