Efficiency enhancement in solution processed small-molecule based organic solar cells utilizing various phthalocyanine–tetrabenzoporphyrin hybrid macrocycles

Abstract

A study on efficiency enhancement in solution processed small-molecule based organic solar cells (OSCs) utilizing various phthalocyanine-tetrabenzoporphyrin hybrid macrocycles is reported. By replacement of aza links at meso position by methine groups, the optical absorption at B band of porphyrinoid complexes is improved, the energy bandgap is enlarged, and stacking of the discotic molecules is probably changed from pseudohexagonal structures to 2-D rectangular lattices. Results from molecular orbital (MO) calculation by using B3LYPoptimized geometries calculated with 6-31G(d) indicate that the intensification of optical absorption and the modification of electronic band structure is mainly due to the difference of MO coefficients at meso positions, resulting in a marked lifting of the degeneracy of the MOs derived from highest occupied molecular orbitals and/or lowest unoccupied molecular orbitals. By controlling the numbers of aza links at meso position, active layer thickness and nanoscale phase separation, the external quantum efficiency at B band and power conversion efficiency of OSCs utilizing phthalocyanine-tetrabenzoporphyrin hybrid macrocycles is improved to 53% and 5.3%, respectively.

Liquid crystals in photovoltaics: a new generation of organic photovoltaics

“…Fujii and co-workers also used Pc DLCs 4d and 4e as additives in classical BHJ thin-film solar cells based on P3HT and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). 69,70 The PV devices show EQEs of 74, 66 and 47% at a wavelength of 540 nm without CnPcH2, with C6PcH2 and with C7PcH2, respectively. The PCE of the solar cell without CnPcH2 was 2.3% with I SC of 8.6 mA cm − 2 , V OC of 0.57 V and FF of 48% that improves to 3.0% with I SC of 12.1 mA cm − 2 , V OC of 0.56 V and FF of 44% with C6PcH2.…”

“…50,68 Owing to their excellent charge-transport property, DLCs have been applied to prepare bilayer and BHJ solar cells. 6 They have also been used as additives in solar cells [69][70][71][72] and also as electrolyte in dye-sensitized solar cell (DSSC). 73 DLCs derived from porphyrin, Pc, TP, hexabenzocoronene and decacyclene have been used as hole-transporting layer while crystalline and liquid crystalline perylene derivatives and C 60 derivatives have commonly been used as electron-transporting materials.…”

“…106 Fujii and co-workers extensively studied various Pc DLCs in PVs. 69,70,[107][108][109][110][111][112][113] They prepared an OPV device based on Pc derivative 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH2) 4d (Figure 8) as donor and the fullerene derivative PC 61 BM as acceptor in 2010. 107 High EQE of 470% in the Q-band absorption region of C6PcH2 and a high energy-conversion efficiency of 3.1% were achieved with different compositions of both donor and acceptor materials.…”

Liquid crystalline and charge transport properties of novel non-peripherally octasubstituted perfluoroalkylated phthalocyanines

“…This has been demonstrated by NMR spin-lattice relaxation studies, which also show that a more ordered system is induced within the columnar axis by reducing the lateral uctuations of the discotic assembly. 25 The DFT calculation of phthalocyanine is reported to show that the spatial distribution of the HOMO is larger than the LUMO at the edge of the phthalocyanine ring (the peripheral sites), 26 and this may provide a possibility of charge hopping from edge to edge of neighbouring phthalocyanine molecules. 24 A single process of charge transport in molecular aggregation is charge transfer between two molecules and this mechanism is explained by Marcus theory where HOMO-HOMO and LUMO-LUMO interactions are key factors described as transfer integral for hole and electron transports, respectively.…”

Compact Modeling of Organic Thin-Film Transistors with Solution Processed Octadecyl Substituted Tetrabenzotriazaporphyrin as an Active Layer

“…Dao el al. [7] reported beneficial properties of one of these compounds, a metal-free octahexyl substituted tetrabenzotriazaporphyrin, 6H 2 TBTAP for high performance small molecule solar cells and also utilized the range of related compounds in which ring nitrogens were replaced systematically by carbon atoms [8]. Metal phthalocyanines and TBTAP derivatives are photosensitive materials.…”