Nanostructured Optoelectronics: Using New Energy States and High-Energy Photons

Semiconductor nanocrystals or quantum dots  are currently being explored for solution processable optoelectronic devices, and as candidates for developing third-generation photovoltaics. While the size-tunable bandgap and solution chemistry affords attractive opportunities, discrete quantum-confined electronic states have been researched for utilizing photons with energy higher than the nominal nanocrystal bandgap. Recently, we discovered new energy states in non-toxic, earth abundant semiconductor nanocrystals, which can be utilized for development of efficient optoelectronic devices like light emitting diodes (LEDs), and extremely-thin photovoltaics and photodetectors for absorption of incident solar radiation. I will summarize the recent efforts in my group on proof-of-concept demonstrations, in single nanoparticle studies and their ensemble counterpart nanoscaled devices, of these new energy states, and advances made towards utilizing high-energy photons and hot-carriers in nanostructured films.