The Nature of Record Efficiency Fluid-Processed Nanotube-Silicon Heterojunctions

Published

April 20, 2015

Author(s)

Jeffrey A. Fagan, Erik K. Hobbie, John M. Harris, Matthew R. Semler

Abstract

The dark transport characteristics of heterojunctions assembled from type, chirality and length-purified single-wall carbon nanotubes (SWCNTs) are used to clarify the nature of nanotube-silicon diodes and solar cells. The freestanding films show remarkable stability in response to large amplitude deformation during fluid processing, including repeated crumpling and folding prior to deposition on patterned silicon substrates, making them well suited for flexible devices. Despite imperfect ideality factors, select films exceed state-of-the-art characteristics, but with a significant and surprising dependence on sample type. The data also suggest that these devices cannot be simply categorized as either Schottky or p-n junctions, and we use scaling and Landauer theory to model the behavior over a broad range of sheet resistance in a manner that highlights the critical role of SWCNT mid-gap states. Our results clarify how SWCNT band-gap engineering can optimize these devices, while suggesting that significant improvement can still be achieved through precise control of the junction morphology.

Citation

ACS Nano

Pub Type

Journals

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DOI Link

Keywords

silicon, single-wall carbon nanotubes, SWCNT, heterojunctions, Landauer theory

Citation

Fagan, J. , Hobbie, E. , Harris, J. and Semler, M. (2015), The Nature of Record Efficiency Fluid-Processed Nanotube-Silicon Heterojunctions, ACS Nano, [online], https://doi.org/10.1021/acs.jpcc.5b02626 (Accessed October 16, 2025)