Room-Temperature Electron Transport in Self-Assembled Sheets of PbSe Nanocrystals with a Honeycomb Nanogeometry

Maryam Alimoradi Jazi (1) , Aditya Kulkarni (2) , Sophia Buhbut Sinai (1) , Joep Peters (1) , Eva Geschiere (2) , Michele Failla (2) , Christophe Delerue (3, 4) , Arjan Houtepen (5) , Laurens Siebbeles (6) , Daniel Vanmaekelbergh (1)

1 Debye Institute for Nanomaterials Science
2 Optoelectronic Materials Section, Department of Chemical Engineering Delft University of Technology
3 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
4 PHYSIQUE - IEMN - Physique - IEMN
5 Deparment of Chemistry, Opto-electronic materials section
6 DelftChemTech

ABSTRACT: It has been shown recently that atomically coherent superstructures of a nanocrystal monolayer in thickness can be prepared by self-assembly of monodisperse PbSe nanocrystals, followed by oriented attachment. Superstructures with a honeycomb nanogeometry are of special interest, as theory has shown that they are regular 2-D semiconductors, but with the highest valence and lowest conduction bands being Dirac-type, that is, with a linear energy-momentum relation around the K-points in the zone. Experimental validation will require cryogenic measurements on single sheets of these nanocrystal monolayer superstructures. Here, we show that we can incorporate these fragile superstructures into a transistor device with electrolyte gating, control the electron density, and measure the electron transport characteristics at room temperature. The electron mobility is 1.5 ± 0.5 cm2 V−1 s−1, similar to the mobility observed with terahertz spectroscopy on freestanding superstructures. The terahertz spectroscopic data point to pronounced carrier scattering on crystallographic imperfections in the superstructure, explaining the limited mobility

Domaines: Physique [physics]; Matière Condensée [cond-mat]

Maryam Alimoradi Jazi, Aditya Kulkarni, Sophia Buhbut Sinai, Joep Peters, Eva Geschiere, et al.. Room-Temperature Electron Transport in Self-Assembled Sheets of PbSe Nanocrystals with a Honeycomb Nanogeometry. Journal of Physical Chemistry C, 2019, 123 (22), pp.14058-14066. ⟨10.1021/acs.jpcc.9b03549⟩. ⟨hal-02162601⟩