Dependence of Band Offset and Open-Circuit Voltage on the Interfacial Interaction between TiO2 and Carboxylated Polythiophenes Export

@article{citeulike:3501679, abstract = {Abstract: The interface of planar TiO2/polymer photovoltaic cells was modified with two carboxylated polythiophenes having different densities of carboxylic acid groups. Both of the interface modifiers increase the photocurrent of the cells but lower the open-circuit voltage. The work function of the TiO2, measured using a Kelvin probe, increases with increasing density of carboxylic acid groups due to the formation of interfacial dipoles pointing toward the TiO2 surface. The formation of interfacial dipoles results in a shift in the band offset at the TiO2/polymer interface, which explains the decrease in the open-circuit voltage. This work demonstrates that care must be taken when using carboxylic acid side groups to attach polymers to titania surfaces in photovoltaic cells. If the density of attachment groups is just enough to attach the polymer, then the benefits of the interface modifier can be realized without substantially decreasing the open-circuit voltage.}, address = {Departments of Chemistry and Materials Science and Engineering, Stanford University, Stanford, California 94305, Department of Chemistry, University of California, Berkeley, Berkeley, California 94720-1460, The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, and National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401-3393}, author = {Liu, Y. and Scully, S. R. and Mcgehee, M. D. and Liu, J. and Luscombe, C. K. and Frechet, J. M. J. and Shaheen, S. E. and Ginley, D. S.}, citeulike-article-id = {3501679}, citeulike-linkout-0 = {http://dx.doi.org/10.1021/jp056576y}, citeulike-linkout-1 = {http://pubs.acs.org/doi/abs/10.1021/jp056576y}, day = {23}, doi = {10.1021/jp056576y}, journal = {J. Phys. Chem. B}, keywords = {carboxyl, exciton, p3ht, tio2}, month = {February}, number = {7}, pages = {3257--3261}, posted-at = {2008-11-10 18:53:02}, priority = {2}, title = {Dependence of Band Offset and Open-Circuit Voltage on the Interfacial Interaction between TiO2 and Carboxylated Polythiophenes}, url = {http://dx.doi.org/10.1021/jp056576y}, volume = {110}, year = {2006} }

TY - JOUR ID - citeulike:3501679 L3 - citeulike-article-id:3501679 N2 - Abstract: The interface of planar TiO2/polymer photovoltaic cells was modified with two carboxylated polythiophenes having different densities of carboxylic acid groups. Both of the interface modifiers increase the photocurrent of the cells but lower the open-circuit voltage. The work function of the TiO2, measured using a Kelvin probe, increases with increasing density of carboxylic acid groups due to the formation of interfacial dipoles pointing toward the TiO2 surface. The formation of interfacial dipoles results in a shift in the band offset at the TiO2/polymer interface, which explains the decrease in the open-circuit voltage. This work demonstrates that care must be taken when using carboxylic acid side groups to attach polymers to titania surfaces in photovoltaic cells. If the density of attachment groups is just enough to attach the polymer, then the benefits of the interface modifier can be realized without substantially decreasing the open-circuit voltage. IS - 7 JF - J. Phys. Chem. B AD - Departments of Chemistry and Materials Science and Engineering, Stanford University, Stanford, California 94305, Department of Chemistry, University of California, Berkeley, Berkeley, California 94720-1460, The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, and National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401-3393 EP - 3261 TI - Dependence of Band Offset and Open-Circuit Voltage on the Interfacial Interaction between TiO2 and Carboxylated Polythiophenes VL - 110 SP - 3257 KW - carboxyl KW - exciton KW - p3ht KW - tio2 AU - Liu, Y AU - Scully, SR AU - Mcgehee, MD AU - Liu, J AU - Luscombe, CK AU - Frechet, JMJ AU - Shaheen, SE AU - Ginley, DS PY - 2006/02/23/ UR - http://dx.doi.org/10.1021/jp056576y ER -