In situ TEM modification of individual silicon nanowires and their charge transport mechanisms

Abstract

Correlating the structure and composition of nanowires grown by the vapour-liquid-solid (VLS) mechanism with their electrical properties is essential for designing nanowire devices. In situ transmission electron microscopy (TEM) that can image while simultaneously measuring the current-voltage (I-V) characteristics of individual isolated nanowires is a unique tool for linking changes in structure with electronic transport. Here we grow and electrically connect silicon nanowires inside a TEM to perform in situ electrical measurements on individual nanowires at room temperature and high temperatures and upon surface oxidation. As-grown, the oxide-free nanowires have nonlinear I-V characteristics. We analyse the I-V measurements in terms of both bulk and injection limited transport models, finding Joule heating effects, bulk-limiting effects for thin nanowires and an injectionlimiting effect for thick wires when high voltages are applied. When the nanowire surface is modified by in situ oxidation, drastic changes occur in electronic properties. We investigate the relation between the observed geometry, changes in the surface and changes in electronic transport, obtaining information for individual nanowires that is inaccessible to other measuring techniques.

Ion‐beam deposited platinum as electrical contacting material in operando electron microscopy experiments at elevated temperatures

“…In electron microcopy, in‐situ and operando methods are becoming increasingly more important. In particular, in transmission electron microscopy (TEM), the introduction of Micro Electronic Mechanical System (MEMS) chip‐based holders has led to the rapid development of methodologies allowing to directly relate structure and composition with material functionality (Alam et al, 2020; Allard et al, 2009; Creemer et al, 2010; Gaulandris et al, 2020; Mele et al, 2016; Niekiel et al, 2017; Vijayan & Aindow, 2019; Yokosawa et al, 2012; Zheng et al, 2022; Zintler et al, 2017). MEMS chips are also employed in conjunction with scanning electron microscopy (SEM) for in‐situ and operando experiments (Mølhave et al, 2004; Schwarzbach et al, 2019).…”

“…One important class of in‐situ /operando experiments involves electrical measurements, yielding the electrical or electrochemical response of materials/devices with nanoscale dimensions (Alam et al, 2020; Haas et al, 2019; Kamaladasa et al, 2015; Zheng et al, 2022). Such experiments have given insight into, for example, solid state battery dynamics (Basak et al, 2022; Hammad Fawey et al, 2016; Wang et al, 2020; Yang et al, 2016; Zhang et al, 2022).…”

Wet‐Etching‐Boosted Charge Storage in 1D Nitride‐Based Systems for Imitating Biological Synaptic Behaviors

“…The optimal model fitted according to the Poole-Frenkel law (Figure 4b) suggests that the surface of the GaN NW is composed of several traps. [45,46] which capture and store charges under continuous voltage biasing. Based on the aforementioned results from TEM observations, material analysis, and I-V sweeps, our results showed a different conduction mechanism.…”

Influence of the Electron Beam and the Choice of Heating Membrane on the Evolution of Si Nanowires’ Morphology in In Situ TEM

“…Therefore, it can be used to obtain a better understanding of the fundamental physical phenomena associated with NW or nanotube materials [ 16 ]. In situ TEM can be used to observe the dynamic changes of NWs [ 16 , 17 , 18 ], control their growth [ 19 , 20 , 21 , 22 , 23 ], and induce the formation of nanotubes [ 24 , 25 ] and nanopores [ 26 ]. For example, Harmand et al observed the atomic layer nucleation by growing GaAs NWs in environmental TEM [ 27 ].…”