Novel Electroactive and Photoactive Molecular Materials Based on Conjugated Donor−Acceptor Structures for Optoelectronic Device Applications

Abstract

Four donor-acceptor functionalized molecular materials with symmetrical structures have been synthesized and investigated for their use in optoelectronic applications. These pi-conjugated molecules consist of one electron-donating moiety, for instance, carbazole, triphenylamine, or phenothiazine at the center, and two acceptors at each side. Introduction of different donor moieties decreases the band gaps allowing a fine-tuning of the optical and electrical properties. These materials exhibit multifunctional properties, such as a red light-emitting behavior and a large photovoltaic effect. Red organic light-emitting diodes were fabricated in a facile nondoping configuration based on these materials. Saturated red-emission is observed with a CIE of x = 0.64 and y = 0.33, and an external quantum efficiency of 0.19%. In addition, our first observation of photovoltaic response in the pi-conjugated molecule with donor-acceptor-donor structure is reported. The organic single-component photovoltaic cells were fabricated and characterized. Their open-circuit voltage and short-circuit current density are 1.1 V and 0.07 mA cm(-2), respectively. The photovoltaic effect corresponds to the absorption characteristics of the compound and depends on the nature of the electron-donating group.

Light‐Emitting Organic Solar Cells Based on a 3D Conjugated System with Internal Charge Transfer

“…Other devices required the simultaneous use of a donor and acceptor material, or different structures to separately obtain one of the two functions. [16][17][18][19][20][21][22] In conclusion, we report a dual-functioning single-molecule LESC displaying both interesting PCE (0.4 %) under intense simulated solar irradiation and EL at moderate voltage. In addition, the latter function occurs in the problematic red region of the visible spectrum.…”

Single Material Solar Cells: the Next Frontier for Organic Photovoltaics?

“…A device ITO/PEDOT:PSS/ 27 /Al illuminated with simulated solar light at 80 mW cm − 2 gave a large V oc (1.14 V) a J sc of 70 μ A cm − 2 and a FF of 24% resulting in a power conversion effi ciency of 0.03%. [ 76 ] Our group has developed several series of star-shaped D-A systems consisting of a triphenylamine core containing a variable number of different peripheral electron acceptor groups. [ 77 , 78 ] A bilayer heterojunction solar cell based on compound 28 as donor material and vacuum deposited C 60 as acceptor gave a power conversion effi ciency of 1.85%.…”

Polythiophene Derivative with Phenothiazine−Vinylene Conjugated Side Chain: Synthesis and Its Application in Field-Effect Transistors

“…16,17 Polymers and organic molecules containing phenothiazine or its derivatives possess unique optoelectronic properties for diverse applications such as OFET, 16 light emitting diodes, 18 photovoltaic devices, 19 and chemiluminescence. which is about three orders higher than that of the common polythiophenes ).…”