Single-step fabrication of quantum funnels via centrifugal colloidal casting of nanoparticle films
| Autor: | Illan J. Kramer, David Zhitomirsky, Jin Young Kim, Hyotcherl Ihee, Michael M. Adachi, Oleksandr Voznyy, Valerio Adinolfi, Brandon R. Sutherland, Jeongho Kim, S. Joon Kwon, Mingjian Yuan, Edward H. Sargent, Kyle W. Kemp, Sjoerd Hoogland, Tae Wu Kim |
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| Rok vydání: | 2015 |
| Předmět: |
Multidisciplinary
Fabrication Materials science General Physics and Astronomy Nanoparticle Context (language use) Nanotechnology General Chemistry Casting General Biochemistry Genetics and Molecular Biology Article Colloid Quantum dot visual_art Centrifugal casting (silversmithing) visual_art.visual_art_medium Ceramic |
| Zdroj: | Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | Centrifugal casting of composites and ceramics has been widely employed to improve the mechanical and thermal properties of functional materials. This powerful method has yet to be deployed in the context of nanoparticles—yet size–effect tuning of quantum dots is among their most distinctive and application-relevant features. Here we report the first gradient nanoparticle films to be constructed in a single step. By creating a stable colloid of nanoparticles that are capped with electronic-conduction-compatible ligands we were able to leverage centrifugal casting for thin-films devices. This new method, termed centrifugal colloidal casting, is demonstrated to form films in a bandgap-ordered manner with efficient carrier funnelling towards the lowest energy layer. We constructed the first quantum-gradient photodiode to be formed in a single deposition step and, as a result of the gradient-enhanced electric field, experimentally measured the highest normalized detectivity of any colloidal quantum dot photodetector. Centrifugal casting is widely used to fabricate functional materials that exhibit built-in spatial gradients due to the variation in material density. Kim et al. use this method to prepare colloidal quantum dot films for the first time, based on which photodetectors with gradient bandgap are built. |
| Databáze: | OpenAIRE |
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