Publication date: 4th October 2024
State-of-the-art organic photovoltaics (OPVs) using π-conjugated polymers and small molecules as electron donors (D) and acceptors (A) exhibit power conversion efficiencies exceeding 19% with external quantum efficiency approaching 90%, and fill factors as high as 0.80. However, this success applies only to a limited set of materials and their combinations; many OPV material systems have inefficient charge generation efficiency. It is still crucial to understand which factors determine the charge generation efficiency of the systems.
We have investigated the charge generation process and its electric field dependence in OPVs. Detailed investigations of OPVs using bulk-heterojunction (BHJ) and planar-heterojunction (PHJ) structures revealed the efficiency-limiting factors of the charge generation process in OPVs. We have found that the charge generation efficiency primarily depends on the energetic difference between the singlet-excited and charge-transfer state at the D/A interface. Insufficient energetic offset causes less efficient, field-dependent charge generation. Second, the relative molecular orientation of acceptor material to donor domains strongly affects charge generation efficiency. For efficient, electric-field independent charge generation, end-on orientation of the acceptor molecules relative to the donor domains is better than face-on packing.
These studies were partially supported by JSPS KAKENHI (JP22K05262, JP18K14301).
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.