Molecular Engineering of Sensitizers and Redox Mediators for Dye Sensitized Solar Cells
소속 :
연사 : Dr. Md. K. Nazeeruddin (Korea University)
일시 : 2013-09-16 16:30 ~
장소 : 500동 목암홀
일 시: 2013년 9월 16일, 오후 4:30
장소: 500동 목암홀
-Abstract-
The dye-sensitized Solar Cell (DSC) is a promising alternative to traditional inorganic semiconductor-based solar cells due to its low cost and high efficiency. In these cells sunlight is absorbed by a dye monolayer located at the junction between a nanostructured electron transporting (n-type) and hole transporting (p-type) phase. The former is a wide band gap semiconductor oxide based on mesoscopic TiO2 nanoparticles and the latter is typically the triiodide/iodide (I3–/I–) redox electrolyte. Upon photo-excitation, the dye injects an electron into the n-type material and the hole is captured by the electrolyte. The electrons then travel through the nanostructure to be collected as current at the external contact, while the holes are transported to the cathode by the redox shuttle. An optimal sensitizer for DSC should absorb all photons below a threshold wavelength of about 920 nm. This limit is derived from thermodynamic considerations showing that the conversion efficiency of any single-junction photovoltaic solar converter peaks at approximately 33 percent near a threshold energy of 1.4 eV. In this respect the dye-sensitized solar cells are however not ideal, which under optimized conditions yields only 11.5% efficiency. The general losses in the dye-sensitized solar cells are due to lack of sensitizer absorption in the near IR region, and the loss-in-potential from the optical band gap to the open-circuit voltage. Therefore the development of novel sensitizers with reduced mismatch between sensitizer absorption and the solar emission spectra, and between the oxidation potential of the redox electrolyte and the sensitizer oxidation potential is paramount to enhancing photocurrent and open circuit potential, respectively. In this talk I will discuss strategies for design and development of new sensitizers and redox mediators that yield a very high short circuit current and open-circuit voltage, ~1000 mV resulting power conversion efficiency of above 12%. Also, the “Power of Perovskite Solar Cell” will be discussed.
장소: 500동 목암홀
-Abstract-
The dye-sensitized Solar Cell (DSC) is a promising alternative to traditional inorganic semiconductor-based solar cells due to its low cost and high efficiency. In these cells sunlight is absorbed by a dye monolayer located at the junction between a nanostructured electron transporting (n-type) and hole transporting (p-type) phase. The former is a wide band gap semiconductor oxide based on mesoscopic TiO2 nanoparticles and the latter is typically the triiodide/iodide (I3–/I–) redox electrolyte. Upon photo-excitation, the dye injects an electron into the n-type material and the hole is captured by the electrolyte. The electrons then travel through the nanostructure to be collected as current at the external contact, while the holes are transported to the cathode by the redox shuttle. An optimal sensitizer for DSC should absorb all photons below a threshold wavelength of about 920 nm. This limit is derived from thermodynamic considerations showing that the conversion efficiency of any single-junction photovoltaic solar converter peaks at approximately 33 percent near a threshold energy of 1.4 eV. In this respect the dye-sensitized solar cells are however not ideal, which under optimized conditions yields only 11.5% efficiency. The general losses in the dye-sensitized solar cells are due to lack of sensitizer absorption in the near IR region, and the loss-in-potential from the optical band gap to the open-circuit voltage. Therefore the development of novel sensitizers with reduced mismatch between sensitizer absorption and the solar emission spectra, and between the oxidation potential of the redox electrolyte and the sensitizer oxidation potential is paramount to enhancing photocurrent and open circuit potential, respectively. In this talk I will discuss strategies for design and development of new sensitizers and redox mediators that yield a very high short circuit current and open-circuit voltage, ~1000 mV resulting power conversion efficiency of above 12%. Also, the “Power of Perovskite Solar Cell” will be discussed.
