Japan Science and Technology Agency (JST) and the University of Tokyo announced on May 16, 2011 that Associate Professor Keisuke Tajima of the University of Tokyo and his colleagues succeeded in improving output voltage of organic thin-film photovoltaic cells by tailoring bilayer interfaces under the support of JST. Details are published online in Nature Materials on May 15, 2011*.
Although thin-film organic photovoltaic cells are featured for the possibilities of flexibility, low cost, and mass production, its challenge is the improvement of conversion efficiency. Interfacial layer between two materials composing the cells is crucial to determine the performance, because light-generated excitons at the interface are separated to electrons and holes to generate electricity.
Researchers connected two films of organic semiconductor P3HT (poly(3-hexylthiophene)) and PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) by film-transfer method without disturbing their flat surface. Each film can further be modified with a surface-segregated monolayer to tune the strength and direction of the surface dipole moment.
Bilayer organic photovoltaic devices were fabricated with interfacial dipole moments that were selected to align upward or downward at the junction between P3HT and PCBM. The open-circuit voltage of the P3HT/PCBM devices was varied from 0.3 to 0.95 V with the direction of dipole moments. The best result far more exceeded the open-circuit voltage of 0.55-0.6V ordinarily obtained in P3HT/PCBM cells without interfacial modification. Improved open-circuit voltage is realized by tailoring bilayer interfaces.
*Akira Tada, Yanfang Geng, Qingshuo Wei, Kazuhito Hashimoto, and Keisuke Tajima, "Tailoring or-ganic heterojunction interfaces in bilayer polymer photovoltaic devices", Nature Materials, Published online: 15 May 2011 | doi: 10.1038/nmat3026
A big nano boost for solar cells
18.01.2017 | Kyoto University and Osaka Gas effort doubles current efficiencies
Multiregional brain on a chip
16.01.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences