Carrier multiplication (CM) or multiexciton generation (MEG) is a process whereby absorption of a single photon produces multiple electron-hole pairs (excitons). CM could benefit a number of solar-energy conversion technologies, most notably photocatalysis and photovoltaics. This presentation overviews recent progress in understanding of the CM process in semiconductor nanocrystals, motivated by an outstanding challenge in this field - the lack of capability to quickly discern between...

Larry Kazmerski, National Renewable Energy Laboratory Solar energy from photovoltaic devices has been around since the early days of the space race, but historically has not had a substantial impact on our global energy scheme. Is that now changing? Dr. Larry Kazmerski is the executive director of Science & Technology Partnerships at the National Renewable Energy Laboratory (NREL) in Golden, CO. He has worked at NREL for over 30 years and was previously the director of the National...

Summary: Power conversion efficiency is one of the most important parameters that can directly affect the overall cost of a PV installation. In the Shockley-Queisser detailed balanced analysis, the power conversion efficiency is limited to ~33% for a single light absorbing layer. The major energy loss occurs from the excess photon energy, energy greater than the semiconductor bandgap, which is lost as heat through electron-phonon coupling and subsequent phonon relaxation and energy...

Summary: Single-walled carbon nanotubes (SWNTs) are two-dimensionally confined quantum wires that have the potential to impact a variety of renewable energy applications. SWCNTs have several fundamental properties that make them attractive for sustainable energy conversion technologies, including high electron and hole mobilities, size-tunable ionization potentials and electron affinities in an energy range relevant to many photovoltaic devices, and optical transitions in the visible and...

Addressing the Challenge of Truly Large Scale Photovoltaics: the Industrial and Thermodynamic Potentials of Organic Solar Cells In order for photovoltaic systems to ultimately provide a considerable fraction of the world’s energy needs they will need to meet a number of stringent performance metrics regarding their cost, efficiency, and robustness. In addition, they will need to be manufactured with very high throughput methods in order to realize the enormous production scales...

Satyendra Kumar gives a talk at the LC2CAM conference about living and manmade photonics systems and liquid crystals in organic photovoltaics.

Graphenes have very attractive properties for photovoltaics. Their tunable bandgap and large optical absorptivity are desirable for efficient light harvesting. Their electronic levels and interfacing with other materials for charge transfer processes can both be tuned with well-developed carbon chemistry. Graphenes have also been shown to have very large charge mobilities, which could be useful for charge collection in solar cells. In addition, they consist of elements abundant on Earth and...