Hot-Carrier Separation in Heterostructure Nanowires observed by Electron-Beam Induced Current

Jonatan Fast; Enrique Barrigon; Mukesh Kumar; Yang Chen; Lars Samuelson; Magnus Borgström; Anders Gustafsson; Steven Limpert; Adam Burke; Heiner Linke

arXiv · 2004.01578

Hot-Carrier Separation in Heterostructure Nanowires observed by Electron-Beam Induced Current

Jonatan Fast·Enrique Barrigon·Mukesh Kumar·Yang Chen·Lars Samuelson·Magnus Borgström·Anders Gustafsson·Steven Limpert·Adam Burke·Heiner Linke

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Abstract

The separation of hot carriers in semiconductors is of interest for applications such as thermovoltaic photodetection and third-generation photovoltaics. Semiconductor nanowires offer several potential advantages for effective hot-carrier separation such as: a high degree of control and flexibility in heterostructure-based band engineering, increased hot-carrier temperatures compared to bulk, and a geometry well suited for local control of light absorption. Indeed, InAs nanowires with a short InP energy barrier have been observed to produce electric power under global illumination, with an open-circuit voltage exceeding the Shockley-Queisser limit. To understand this behaviour in more detail, it is necessary to maintain control over the precise location of electron-hole pair-generation in the nanowire. In this work we perform electron-beam induced current measurements with high spatial resolution, and demonstrate the role of the InP barrier in extracting energetic electrons. We interprete the results in terms of hot-carrier separation, and extract estimates of the hot carrier mean free path.

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Jonatan Fast, Enrique Barrigon, Mukesh Kumar, Yang Chen, Lars Samuelson, Magnus Borgström, Anders Gustafsson, Steven Limpert, Adam Burke, Heiner Linke. 2020-04-03. Hot-Carrier Separation in Heterostructure Nanowires observed by Electron-Beam Induced Current. https://arxiv.org/abs/2004.01578

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