Photoinduced Charge Separation in Organic–Organic Heterojunctions Based on Porphyrin Electropolymers. Spectral and Time Dependent Surface Photovoltage Study.

Abstract

Photoactive heterojunctions formed by porphyrin polymers were electrochemically generated and analyzed by both transient and spectral dependent surface photovoltage. Indium tin oxide/organic polymer heterojunction photovoltages showed to be dependent on the presence of Zn (II) as central metal on the porphyrin polymer structure. The porphyrin electropolymers were also successfully formed on the top of a poly 3,4-ethylenedioxythiophene layer, generated by electropolymerization. The presence of the hole transport polymer dramatically altered the formation and diffusion process of the photocarriers created by excitation of the porphyrin films. A marked increase in the generated photovoltages was observed when the porphyrin electropolymer external surfaces were modified with a layer of a strong electron acceptor (C 60 buckminsterfullerene), showing that these heterojunctions could be used in the development of new solar energy technologies.

Photodynamic Inactivation of Bacteria Using Novel Electrogenerated Porphyrin-Fullerene C60 Polymeric Films

“…The CV shape of the first TCP layer is similar to that reported before, while the bilayer presents contributions to the oxidation–reduction faradaic currents from both layers. In the same way, TCP/ZnTCP bilayers were formed by electrodeposition of a first layer of TCP and a second one of ZnTCP. , As it can be seen in Figure S1b, formation of the second layer of ZnTCP produces an increase in the oxidation/reduction currents of the film (with respect to that observed for the first layer) when it is placed in a solution containing only a support electrolyte. This observation confirms the deposition of ZnTCP.…”

“…This observation confirms the deposition of ZnTCP. Similar electroactive layers were proposed for the construction of multicomponent supramolecular architectures suitable for efficient generation of surface photovoltages. , …”

Nanoscale Characterization and Unexpected Photovoltaic Behavior of Low Band Gap Sulfur-Overrich-Thiophene/Benzothiadiazole Decamers and Polymers

“…45 The very recently reported donor−acceptor conjugated DPP-thieno-TTF copolymer displays a conversion efficiency of 0.3% in the SMOC device and of 1.8 in the BHJ device for the blend of the same copolymer with PC 71 BM. 25 Although phase segregation is not a prerequisite to obtain the generation of a measurable photovoltage in single-material polymeric films, 46,47 owing to the fact that compounds 1−6 are photoactive materials in SMOC devices, donor and acceptor nanodomains must be present in their spin-coated films in order to ensure not only light absorption and charge separation but also the basic function of charge transport. In other words, the self-assembled films must contain substructures on a nanometer scale (that is, a scale comparable to the mean exciton diffusion length) having the appropriate organization for separate hole and electron transport.…”

Proton‐Dependent Switching of a Novel Amino Chlorin Derivative as a Fluorescent Probe and Photosensitizer for Acidic Media

“…Cyclic voltammetry (CV) experiments were performed with an Autolab potentiostat–galvanostat (Electrochemical Instruments, Utrecht, The Netherlands) using a Pt working electrode, a silver wire reference electrode, and a Pt coil counter electrode . Electrochemical studies of TPCF 20 ‐NMe 2 were carried out at room temperature by CV in deoxygenated DMF containing 0.1 m tetra‐ n ‐butylammonium hexafluorophosphate (TBAHFP) as the supporting electrolyte.…”