Organic materials characterized by an extended p-conjugation are extensively investigated for their applications in organic and molecular electronics. Soluble organic molecules are promising materials for electronics since their easy synthesis and deposition methods make them compatible with low cost fabrication technology. Recently we described the synthesis and the use of anthracene-containing semiconductors as active layer in photovoltaic devices and the photobehaviour in solution.The present report deals with the chemical-physical properties of symmetric and asymmetric ethynylanthracene derivatives in thin film, studied to evaluate their potential efficiency in organic solar cells. The difference between the spectral and photophysical properties of the studied compounds in solution and in thin film (by spin-coating procedure) is discussed on the basis of H- and J-type aggregation. These compounds could be used as electron-donors in bulk heterojunction active layer with the most used electron-acceptor, [60]PCBM. An efficient photoinduced electron transfer (ET) was hypothesized on the basis of the quenching of the fluorescence intensity of the acetylene derivatives on increasing the [60]PCBM concentration in stationary experiments. Further information on ET came from preliminary measurements of ultrafast (fs) transient spectroscopy in solution and in thin films. Another important aspect for determining the efficiency of the solar cell is the durability of the film under solar light exposition for a long time. This was studied by fluorescence time base scanning measurements and absorption UV-VIS spectra recorded before and after exposure of the films to the light of a solar simulator. Finally some mixtures of the studied compounds and with polymers and other organic molecules were studied to improve the absorbance spectra overlap with the solar emission spectrum. The obtained results are reported and discussed.
Ethynyl anthracene derivatives for the active layer of OPV cells: photobehavior in solutions, thin film and for ternary mixtures
FLAMINI, REBECCA;MARROCCHI, Assunta;CARLOTTI, BENEDETTA;SPALLETTI, Anna
2013
Abstract
Organic materials characterized by an extended p-conjugation are extensively investigated for their applications in organic and molecular electronics. Soluble organic molecules are promising materials for electronics since their easy synthesis and deposition methods make them compatible with low cost fabrication technology. Recently we described the synthesis and the use of anthracene-containing semiconductors as active layer in photovoltaic devices and the photobehaviour in solution.The present report deals with the chemical-physical properties of symmetric and asymmetric ethynylanthracene derivatives in thin film, studied to evaluate their potential efficiency in organic solar cells. The difference between the spectral and photophysical properties of the studied compounds in solution and in thin film (by spin-coating procedure) is discussed on the basis of H- and J-type aggregation. These compounds could be used as electron-donors in bulk heterojunction active layer with the most used electron-acceptor, [60]PCBM. An efficient photoinduced electron transfer (ET) was hypothesized on the basis of the quenching of the fluorescence intensity of the acetylene derivatives on increasing the [60]PCBM concentration in stationary experiments. Further information on ET came from preliminary measurements of ultrafast (fs) transient spectroscopy in solution and in thin films. Another important aspect for determining the efficiency of the solar cell is the durability of the film under solar light exposition for a long time. This was studied by fluorescence time base scanning measurements and absorption UV-VIS spectra recorded before and after exposure of the films to the light of a solar simulator. Finally some mixtures of the studied compounds and with polymers and other organic molecules were studied to improve the absorbance spectra overlap with the solar emission spectrum. The obtained results are reported and discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
