Solution-Processed Transistors Using Colloidal Nanocrystals with Composition-Matched Molecular "Solders": Approaching Single Crystal Mobility.
Crystalline silicon-based complementary metal-oxide-semiconductor transistors have become a dominant platform for today's electronics. For such devices, expensive and complicated vacuum processes are used in the preparation of active layers. This increases cost and restricts the scope of applications. Here, we demonstrate high-performance solution-processed CdSe nanocrystal (NC) field-effect transistors (FETs) that exhibit very high carrier mobilities (over 400 cm(2)/(V s)). This is comparable to the carrier mobilities of crystalline silicon-based transistors. Furthermore, our NC FETs exhibit high operational stability and MHz switching speeds. These NC FETs are prepared by spin coating colloidal solutions of CdSe NCs capped with molecular solders [Cd2Se3](2-) onto various oxide gate dielectrics followed by thermal annealing. We show that the nature of gate dielectrics plays an important role in soldered CdSe NC FETs. The capacitance of dielectrics and the NC electronic structure near gate dielectric affect the distribution of localized traps and trap filling, determining carrier mobility and operational stability of the NC FETs. We expand the application of the NC soldering process to core-shell NCs consisting of a III-V InAs core and a CdSe shell with composition-matched [Cd2Se3](2-) molecular solders. Soldering CdSe shells forms nanoheterostructured material that combines high electron mobility and near-IR photoresponse.
Department of Chemistry and James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.
Jaeyoung
J
Jang
Department of Chemistry and James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.
Dmitriy S
DS
Dolzhnikov
Department of Chemistry and James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.
Wenyong
W
Liu
Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
Sooji
S
Nam
Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
Moonsub
M
Shim
Department of Chemistry and James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.|Center for Nanoscale Materials, Argonne National Lab , Argonne, Illinois 60439, United States.
Dmitri V
DV
Talapin
electron mobility; field-effect transistor; inorganic ligands; molecular solder; nanocrystals; nanoheterostructures; switching speed