Bulk Heterojunction versus Diffused Bilayer: The Role of Device Geometry in Solution p-Doped Polymer-Based Solar Cells.
We exploit the effect of molecular p-type doping of P3HT in diffused bilayer (DB) polymer solar cells. In this alternative device geometry, the p-doping is accomplished in solution by blending the F4-TCNQ with P3HT. The p-doping both increases the film conductivity and reduces the potential barrier at the interface with the electrode. This results in an excellent power conversion efficiency of 4.02%, which is an improvement of ∼48% over the p-doped standard bulk heterojunction (BHJ) device. Combined VOC-light intensity dependence measurements and Kelvin probe force microscopy reveal that the DB device configuration is particularly advantageous, if compared to the conventional BHJ, because it enables optimization of the donor and acceptor layers independently to minimize the effect of trapping and to fully exploit the improved transport properties.
†Dipartimento di Matematica e Fisica "Ennio De Giorgi", Università del Salento, via Arnesano, 73100 Lecce, Italy.|‡CBN - Center for Biomolecular Nanotechnologies, Italian Institute of Technology, Energy Platform, Via Barsanti sn -73010 Arnesano, Lecce, Italy.
Anna
A
Loiudice
‡CBN - Center for Biomolecular Nanotechnologies, Italian Institute of Technology, Energy Platform, Via Barsanti sn -73010 Arnesano, Lecce, Italy.|§NNL CNR-Istituto Nanoscienze, c/o Distretto Tecnologico, via per Arnesano km.5, 73100 Lecce, Italy.
Aurora
A
Rizzo
⊥NNL-CNR Istituto di Nanoscienze, c/o Dip. Fisica Ed. G. Marconi, La Sapienza University, Roma, Italy.|#Center for Life NanoScience@LaSapienza, Italian Institute of Technology, Viale Regina Elena 295, Roma, Italy.
Mariano
M
Biasiucci
†Dipartimento di Matematica e Fisica "Ennio De Giorgi", Università del Salento, via Arnesano, 73100 Lecce, Italy.|‡CBN - Center for Biomolecular Nanotechnologies, Italian Institute of Technology, Energy Platform, Via Barsanti sn -73010 Arnesano, Lecce, Italy.|§NNL CNR-Istituto Nanoscienze, c/o Distretto Tecnologico, via per Arnesano km.5, 73100 Lecce, Italy.
Giuseppe
G
Gigli
conductivity; diffused bilayers; doping; polymer solar cells