DMCA
Poster TRANSPORT CHARACTERISTICS OF COLLOIDAL NANOCRYSTAL TETRAPODS IN PLANAR ELECTRODE DEVICES
BibTeX
@MISC{Krahne_postertransport,
author = {Roman Krahne and Antonio Della Torre and Luigi Carbone and Liberato Manna},
title = {Poster TRANSPORT CHARACTERISTICS OF COLLOIDAL NANOCRYSTAL TETRAPODS IN PLANAR ELECTRODE DEVICES},
year = {}
}
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Abstract
In recent years, there has been a remarkable advancement in the ability to grow anisotropic nanocrystals, such as rods, tetrapods,[1] and nanocrystals with even more complex branched shapes.[2] Experiments on such nanocrystals have demonstrated that they hold a great potential as active materials in single-electron transistors[3-5]. Tetrapods are an especially interesting class of nanocrystals due to their unique shape, where four arms branch out at tetrahedral angles from a central core (Fig. 1a). Drop casted onto a planar surface the tetrapods self align with one arm pointing upwards and three legs on the surface. By fabricating contacts to the individual arms, the tetrapods can function as multiterminal electronic devices. In this work we position CdTe tetrapods [1] in between three planar electrodes on a Si/SiO2 substrate and investigate the electronic properties of such devices. The electrodes, fabricated by electron-beam lithography and subsequent metal evaporation, point towards a central gap of 80 nm (see Fig. 1b). To position the tetrapods into the gap we cast a drop of the nanocrystal solution onto the substrate and use the technique of electrostatic trapping [6, 7] to attract the tetrapods in between the electrodes. The transport measurements on such multiterminal devices were performed at room and cryogenic temperatures. In the I-V characteristics of the tetrapods at low temperature (Fig. 2) we find a zero-current plateau of some hundred mV and a strong increase in conductivity near the bandgap energy ( around 1.7 eV obtained from lightabsorption measurements). These large energy scales, that lead to strongly non-linear I-V curves at room temperature, make such a device type suitable for applications under ambient conditions. We used the Si/SiO2 substrate as a gate electrode and discuss the effect gating the tetrapod devices. References: 1. Manna, L., et al., Controlled growth of tetrapod-branched inorganic nanocrystals.
Keyphrases
si sio2 substrate tetrahedral angle central gap electron-beam lithography electronic property unique shape zero-current plateau tetrapod-branched inorganic nanocrystals device type suitable nanocrystal solution recent year multiterminal electronic device anisotropic nanocrystals large energy scale arm pointing upwards ambient condition lightabsorption measurement point towards arm branch transport measurement remarkable advancement single-electron transistor multiterminal device planar surface active material individual arm position cdte tetrapod interesting class central core subsequent metal evaporation strong increase tetrapod device i-v characteristic gate electrode low temperature cryogenic temperature room temperature non-linear i-v curve bandgap energy et al
