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Anders Mikkelsen. Portrait.

Anders Mikkelsen

Professor

Anders Mikkelsen. Portrait.

Optical-Beam-Induced Current in InAs/InP Nanowires for Hot-Carrier Photovoltaics

Author

  • Jonatan Fast
  • Yen Po Liu
  • Yang Chen
  • Lars Samuelson
  • Adam M. Burke
  • Heiner Linke
  • Anders Mikkelsen

Summary, in English

Using the excess energy of charge carriers excited above the band edge (hot carriers) could pave the way for optoelectronic devices, such as photovoltaics exceeding the Shockley-Queisser limit or ultrafast photodetectors. Semiconducting nanowires show promise as a platform for hot-carrier extraction. Proof of principle photovoltaic devices have already been realized based on InAs nanowires, using epitaxially defined InP segments as energy filters that selectively transmit hot electrons. However, it is not yet fully understood how charge-carrier separation, relaxation, and recombination depend on device design and on the location of optical excitation. Here, we introduce the use of an optical-beam-induced current (OBIC) characterization method, employing a laser beam focused close to the diffraction limit and a high precision piezo stage, to study the optoelectric performance of the nanowire device as a function of the position of excitation. The photocurrent response agrees well with modeling based on hot-electron extraction across the InP segment via diffusion. We demonstrate that the device is capable of producing power and estimate the spatial region within which significant hot-electron extraction can take place to be on the order of 300 nm away from the barrier. When comparing to other experiments on similar nanowires, we find good qualitative agreement, confirming the interpretation of the device function, while the extracted diffusion length of hot electrons varies. Careful control of the excitation and device parameters will be important to reach the potentially high device performance theoretically available in these systems.

Department/s

  • LTH Profile Area: Nanoscience and Semiconductor Technology
  • NanoLund: Centre for Nanoscience
  • Solid State Physics
  • Synchrotron Radiation Research
  • LTH Profile Area: Engineering Health
  • Faculty of Engineering, LTH
  • LTH Profile Area: Photon Science and Technology

Publishing year

2022-06-27

Language

English

Pages

7728-7734

Publication/Series

ACS Applied Energy Materials

Volume

5

Issue

6

Document type

Journal article

Publisher

The American Chemical Society (ACS)

Topic

  • Condensed Matter Physics (including Material Physics, Nano Physics)

Keywords

  • hot carrier
  • InAs
  • InP
  • nanowires
  • optical-beam-induced current
  • photovoltaic
  • scanning photocurrent microscopy

Status

Published

ISBN/ISSN/Other

  • ISSN: 2574-0962