Nanowires enabling strained photovoltaics

Journal Article · Mon Apr 21 04:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4871458· OSTI ID:22262581

Greil, J.; Bertagnolli, E.; Birner, S. ^[1]

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1. nextnano GmbH, Südmährenstr. 21, 85586 Poing (Germany)

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.

• OSTI ID: 22262581
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 16 Vol. 104; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHARGE CARRIERS
GERMANIUM
P-N JUNCTIONS
PHOTOVOLTAIC EFFECT
QUANTUM EFFICIENCY
QUANTUM WIRES
STRAINS