The Fine-Structure Constant as a Ruler for the Band-Edge Light Absorption Strength of Bulk and Quantum-Confined Semiconductors

Prins PT, Alimoradi Jazi M, Killilea NA, Evers WH, Geiregat P, Heiß W, Houtepen AJ, Delerue C, Hens Z, Vanmaekelbergh D (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Nano Letters American Chemical Society

Book Volume: 21

Pages Range: 9426-9432

Journal Issue: 22

DOI: 10.1021/acs.nanolett.1c02682

Abstract

Low-dimensional semiconductors have found numerous applications in optoelectronics. However, a quantitative comparison of the absorption strength of low-dimensional versus bulk semiconductors has remained elusive. Here, we report generality in the band-edge light absorptance of semiconductors, independent of their dimensions. First, we provide atomistic tight-binding calculations that show that the absorptance of semiconductor quantum wells equals mπα (m = 1 or 2 with α as the fine-structure constant), in agreement with reported experimental results. Then, we show experimentally that a monolayer (superlattice) of quantum dots has similar absorptance, suggesting an absorptance quantum of mπα per (confined) exciton diameter. Extending this idea to bulk semiconductors, we experimentally demonstrate that an absorptance quantum equal to mπα per exciton Bohr diameter explains their widely varying absorption coefficients. We thus provided compelling evidence that the absorptance quantum πα per exciton diameter rules the band-edge absorption of all direct semiconductors, regardless of their dimension.

Authors with CRIS profile

Niall Andrew Killilea Institute Materials for Electronics and Energy Technology (i-MEET) Wolfgang Heiß Professur für Werkstoffwissenschaften (lösungsprozessierte Halbleitermaterialien)

Involved external institutions

Debye Institute for Nanomaterials Science NL Netherlands (NL) Delft University of Technology (TU Delft) NL Netherlands (NL) Universiteit Gent (UGent) / Ghent University BE Belgium (BE) LILLE 1 University - Science and Technology FR France (FR)

How to cite

APA:

Prins, P.T., Alimoradi Jazi, M., Killilea, N.A., Evers, W.H., Geiregat, P., Heiß, W.,... Vanmaekelbergh, D. (2021). The Fine-Structure Constant as a Ruler for the Band-Edge Light Absorption Strength of Bulk and Quantum-Confined Semiconductors. Nano Letters, 21(22), 9426-9432. https://dx.doi.org/10.1021/acs.nanolett.1c02682

MLA:

Prins, P. Tim, et al. "The Fine-Structure Constant as a Ruler for the Band-Edge Light Absorption Strength of Bulk and Quantum-Confined Semiconductors." Nano Letters 21.22 (2021): 9426-9432.

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