Publication date: 1st April 2013
Quantum dot sensitized solar cells (QDSSCs) enjoy increasing popularity [1,2] as a serious alternative to their dye-sensitized homologues. A quantum dot (QD) sensitizer can be any small size semiconductor where quantum confinement effects demonstrate themselves by an important change in the energy band gap and subsequent modification of the light absorption threshold. However, the term usually refers to a few metal chalcogenides like CdS, CdSe, ZnS and PbS. Combination of these QDs can offer panchromatic sensitization and exploitation of the solar spectrum. Most importantly, combination of semiconductors offers structures, which guarantee greater stability while they increase efficiency by inducing photogenerated charge carrier separation. A well established efficient combination of QDs involves CdS and CdSe together with a ZnS passivation layer on the top. Many aspects of this combination have been thoroughly studied in the past but open questions are still on stage [3] and make an interesting subject of research.
In this presentation, we will present our recent experience on the study of combined CdS-CdSe-ZnS QD sensitizers of nanoparticulate titania as applied to liquid electrolyte QDSSCs. Particular emphasis will be placed on the study of semiconductor interfaces by several spectroscopic techniques including micro-Raman. The order of materials deposition and mixing and the effect of annealing, the latter not being sufficiently stressed in literature, will be examined as important parameters greatly affecting cell efficiency.
Even though, most of our results are being obtained with photoanodes carrying nanoparticulate titania, some other forms of nanostructured titania will be critically examined in an effort to set off their advantages and disadvantages.
Finally, a typical liquid electrolyte QDSSC is made of a photoanode and a counter electrode separated by a thin thermoplastic gasket of thickness of a few tens of micrometers, similarly to their dye-sensitized homologues. We consider this geometry too restrictive. This geometry is understandable in the case of dye-sensitized solar cells, which utilize organic electrolytes with small ionic conductivity. In the case of QDSSCs, which employ aqueous polysulfide electrolytes with high ionic conductivity, other cell geometries can be envisaged and will be discussed.
[1] Sudhagar P et al. Interfacial engineering of quantum dot-sensitized TiO2 fibrous electrodes for futuristic photoanodes in photovoltaic applications. J. Mater. Chem., 2012,22, 14228-14235 [2] Kamat P.V. Boosting the Efficiency of Quantum Dot Sensitized Solar Cells through Modulation of Interfacial Charge Transfer. Acc.Chem.Res. 2012, 45, 1906–1915
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.