Low Voltage, Hysteresis Free, and High Mobility Transistors from All-Inorganic Colloidal Nanocrystals

Abstract

High-mobility solution-processed all-inorganic solid state nanocrystal (NC) transistors with low operation voltage and near-zero hysteresis are demonstrated using high-capacitance ZrO_x and hydroxyl-free Cytop gate dielectric materials. The use of inorganic capping ligands (In₂Se₄^2- and S^2-) allowed us to achieve high electron mobility in the arrays of solution-processed CdSe nanocrystals. We also studied the hysteresis behavior and switching speed of NC-based field effect devices. Collectively, these analyses helped to understand the charge transport and trapping mechanisms in all-inorganic NCs arrays. Finally, we have examined the rapid thermal annealing as an approach toward high-performance solution-processed NCs-based devices and demonstrated transistor operation with mobility above 30 cm²/(V s) without compromising low operation voltage and hysteresis.