[1]Benzothieno[3,2-b]benzothiophene-Based Organic Dyes for Dye-Sensitized Solar Cells

Abstract

Three new metal-free organic dyes with the [1]benzothieno[3,2-b]benzothiophene (BTBT) π-bridge, having the structure donor-π-acceptor (D-π-A) and labeled as 19, 20 and 21, have been designed and synthesized for application in dye-sensitized solar cells (DSSC). Once the design of the π-acceptor block was fixed, containing the BTBT as the π-bridge and the cyanoacrylic group as the electron acceptor and anchoring unit, we selected three donor units with different electron-donor capacity, in order to assemble new chromophores with high molar extinction coefficients (ε), whose absorption features well reflect the good performance of the final DSSC devices. Starting with the 19 dye, which shows a molar extinction coefficient ε of over 14,000 M(-1) cm(-1) and takes into account the absorption maximun at the longer wavelength, the substitution of the BFT donor unit with the BFA yields a great enhancement of absorptivity (molar extinction coefficient ε > 42,000 M(-1) cm(-1)), until reaching the higher value (ε > 69,000 M(-1) cm(-1)) with the BFPhz donor unit. The good general photovoltaic performances obtained with the three dyes highlight the suitable properties of electron-transport of the BTBT as the π-bridge in organic chromophore for DSSC, making this very cheap and easy to synthesize molecule particularly attractive for efficient and low-cost photovoltaic devices.

Structures, Properties, and Device Applications for [1]Benzothieno[3,2‐b]Benzothiophene Derivatives

“…BTBT derivatives are now being acted as channel layer of OFETs, UV‐responsive materials for photodetectors/phototransistors, donor of organic charge‐transfer (CT) complexes, and even the π‐bridge group for dye‐sensitized solar cells. [ 12–15 ] Therefore, we would like to summarize the development of derivatives of BTBT scaffold, and elucidate their chemical and physical properties, especially putting emphasis on the processing techniques of high‐performance OFETs based on BTBT derivatives. Figure shows the fabrication techniques and applications of BTBT‐based electronic and optoelectronic devices.…”

Assembly with copper(ii) ions and D–π–A molecules on a graphene surface for ultra-fast acetic acid sensing at room temperature

“…As we expected, 4HQ-rGO exhibited a higher response, which was ascribed to the supramolecular assembly of rGO with the dipolar molecule, 4HQ. As reported, 36,37 the D-p-A structure of 4HQ accelerated the electronic transportation between graphene and acetic acid molecules. Moreover, the introduction of the Cu 2+ ions further improved the gas sensitivity and dramatically shortened the response and recovery times since the electron-decient Cu 2+ promoted the charge transfer between the small molecules and graphene nanosheets.…”

Synthesis and Investigation of Electro-Optical Properties of H-Shape Dibenzofulvene Derivatives

“…The combination of several organic structural motifs such as phenylene-vinylene, thiophene, pyrrole, triarylamines and fluorene derivates is widely studied because it gives life to a very important class of electroactive and photoactive compounds, used in several sector of optoelectronics, such as organic light-emitting diodes (OLED) [ 1 ], organic field-effect transistors (OFET) [ 2 ], electrochromic and electrofluorochromic devices (ECDs and EFCDs) [ 3 , 4 , 5 ], dye-sensitized solar cells (DSSCs) [ 6 , 7 , 8 ], as well as used as fluorescent probes in bioimaging applications [ 9 , 10 , 11 ]. In particular, in the last decade, great attention was paid to a large variety of organic molecule semiconductors with hole-transporting properties since they play a pivotal part for achieving, for example, high performances in perovskite solar cells (PSCs), ensuring efficient hole extraction and transportation, and the suppression of photogenerated carrier recombination [ 12 , 13 , 14 ].…”