Persistent Coulomb Blockade Across the Metal-Insulator Transition in Nanoparticle Solids

Nanoparticle (NP) solids in opto-electronic and photovoltaic applications have disadvantageously low carrier mobilities. The mobility is suppressed by the disorder driving the NP solids insulators. A Filling-Controlled (FC) Coulomb blockade further suppresses transport at integer fillings. Transport at non-integer fillings can be improved by driving NP solids across a Disorder-Controlled Metal-Insulator Transition (DC-MIT) into their Metallic Phase by enhancing the kinetic energy to overcome the disorder and thus delocalizing the electron wavefunctions. However, the evolution of the FC-Coulomb blockade at integer fillings across the DC-MIT has not been analyzed yet, leaving the question open whether the FC-Coulomb blockade dissolves or persists in some form as the electron wavefunctions delocalize when the DC-MIT is crossed. The work reported here explores this question of how the FC-Coulomb blockade evolves across the DC-MIT by analyzing transport in the Insulating Phase by our Hierarchical Nanoparticle Transport Simulator, and in the Metallic Phase by Dynamical Mean-Field Theory. Remarkably, the FC-Coulomb blockade is found to persist across the DC-MIT.