Electronic Transport in Nanocrystal Solids

With nanoscale building blocks, "artificial atoms", that have very novel properties, it will be possible to engineer materials that will be better than those we already make. Solids are first divided between "insulating" and "conducting" which refers to their ability to conduct electricity. The first step is then to understand how charge flows in nano-engineered solids. 

We investigate the electrical properties of solids made by assembly of semiconductor quantum dots and of metallic nanoparticles. Electrons hop between nanoparticles using thermal energy to overcome the bumps along the way. By changing the temperature, we learn about the origin of the bumps acting on the electrons, position, energy and electrostatic forces. Electrons are also sensitive to magnetic fields and thus the effect on the current can be used to detect small magnetic fields.

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To make it easier for the electrons to hop between nanocrystals, we exchange the molecules in between with short molecules by the "dipping technique" (JPCB 2003) , or replace them with an inorganic material by "atomic layer deposition" (Adv. Mat. 2009)