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Title: Nanowires enabling strained photovoltaics

Abstract

Photovoltaic nano-devices have largely been relying on charge separation in conventional p-n junctions. Junction formation via doping, however, imposes major challenges in process control. Here, we report on a concept for photovoltaic energy conversion at the nano scale without the need for intentional doping. Our approach relies on charge carrier separation in inhomogeneously strained germanium nanowires (Ge NWs). This concept utilizes the strain-induced gradient in bandgap along tapered NWs. Experimental data confirms the feasibility of strain-induced charge separation in individual vapor-liquid-solid grown Ge NW devices with an internal quantum efficiency of ∼5%. The charge separation mechanism, though, is not inherently limited to a distinct material. Our work establishes a class of photovoltaic nano-devices with its opto-electronic properties engineered by size, shape, and applied strain.

Authors:
; ;  [1];  [2]
  1. Institute of Solid State Electronics, Vienna University of Technology, Floragasse 7, 1040 Vienna (Austria)
  2. nextnano GmbH, Südmährenstr. 21, 85586 Poing (Germany)
Publication Date:
OSTI Identifier:
22262581
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CHARGE CARRIERS; GERMANIUM; PHOTOVOLTAIC EFFECT; P-N JUNCTIONS; QUANTUM EFFICIENCY; QUANTUM WIRES; STRAINS

Citation Formats

Greil, J., Bertagnolli, E., Lugstein, A., E-mail: alois.lugstein@tuwien.ac.at, and Birner, S. Nanowires enabling strained photovoltaics. United States: N. p., 2014. Web. doi:10.1063/1.4871458.
Greil, J., Bertagnolli, E., Lugstein, A., E-mail: alois.lugstein@tuwien.ac.at, & Birner, S. Nanowires enabling strained photovoltaics. United States. doi:10.1063/1.4871458.
Greil, J., Bertagnolli, E., Lugstein, A., E-mail: alois.lugstein@tuwien.ac.at, and Birner, S. 2014. "Nanowires enabling strained photovoltaics". United States. doi:10.1063/1.4871458.
@article{osti_22262581,
title = {Nanowires enabling strained photovoltaics},
author = {Greil, J. and Bertagnolli, E. and Lugstein, A., E-mail: alois.lugstein@tuwien.ac.at and Birner, S.},
abstractNote = {Photovoltaic nano-devices have largely been relying on charge separation in conventional p-n junctions. Junction formation via doping, however, imposes major challenges in process control. Here, we report on a concept for photovoltaic energy conversion at the nano scale without the need for intentional doping. Our approach relies on charge carrier separation in inhomogeneously strained germanium nanowires (Ge NWs). This concept utilizes the strain-induced gradient in bandgap along tapered NWs. Experimental data confirms the feasibility of strain-induced charge separation in individual vapor-liquid-solid grown Ge NW devices with an internal quantum efficiency of ∼5%. The charge separation mechanism, though, is not inherently limited to a distinct material. Our work establishes a class of photovoltaic nano-devices with its opto-electronic properties engineered by size, shape, and applied strain.},
doi = {10.1063/1.4871458},
journal = {Applied Physics Letters},
number = 16,
volume = 104,
place = {United States},
year = 2014,
month = 4
}
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