Optical determination of crystal phase in semiconductor nanocrystals

Sung Jun Lim, André Schleife, Andrew M. Smith

Research output: Contribution to journalArticlepeer-review

32 Scopus citations

Abstract

Optical, electronic and structural properties of nanocrystals fundamentally derive from crystal phase. This is especially important for polymorphic II-VI, III-V and I-III-VI 2 semiconductor materials such as cadmium selenide, which exist as two stable phases, cubic and hexagonal, each with distinct properties. However, standard crystallographic characterization through diffraction yields ambiguous phase signatures when nanocrystals are small or polytypic. Moreover, diffraction methods are low-throughput, incompatible with solution samples and require large sample quantities. Here we report the identification of unambiguous optical signatures of cubic and hexagonal phases in II-VI nanocrystals using absorption spectroscopy and first-principles electronic-structure theory. High-energy spectral features allow rapid identification of phase, even in small nanocrystals (∼2 nm), and may help predict polytypic nanocrystals from differential phase contributions. These theoretical and experimental insights provide simple and accurate optical crystallographic analysis for liquid-dispersed nanomaterials, to improve the precision of nanocrystal engineering and improve our understanding of nanocrystal reactions.

Original languageEnglish
Article number14849
JournalNature Communications
Volume8
DOIs
StatePublished - 17 May 2017

Bibliographical note

Publisher Copyright:
© 2017 The Author(s).

Fingerprint

Dive into the research topics of 'Optical determination of crystal phase in semiconductor nanocrystals'. Together they form a unique fingerprint.

Cite this