Stoichiometric Doping of Highly Coupled Cu2–xS Nanocrystal Assemblies
| Autor: | Hanna Park, HanKyul Lee, Jeonghun Kwak, Hyobin Yoo, Agni Raj Koirala, Wansoo Huh, Hyunwoo Jo, Jong Ik Lee, Minkyoung Lee, Seunghan Kim, Juhyung Park, Jeehye Yang, Moon Sung Kang |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Doping chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Copper 0104 chemical sciences Copper sulfide chemistry.chemical_compound Chemical engineering Nanocrystal chemistry Electrical resistivity and conductivity Seebeck coefficient Thermoelectric effect General Materials Science 0210 nano-technology Stoichiometry |
| Zdroj: | ACS Applied Materials & Interfaces. 13:26330-26338 |
| ISSN: | 1944-8252 1944-8244 |
| Popis: | The hole density of individual copper sulfide nanocrystals (Cu2-xS NCs) is determined from the stoichiometric mismatch (x) between copper and sulfide atoms. Consequently, the electronic properties of the material vary over a range of x. To exploit Cu2-xS NCs in devices, assemblies of NCs are typically required. Herein, we investigate the influence of x, referred to as the stoichiometric doping effect, on the structural, optical, electrical, and thermoelectric properties of electronically coupled Cu2-xS NC assemblies. The doping process is done by immersing the solid NC assemblies into a solution containing a Cu(I) complex for different durations (0-10 min). As Cu+ gradually occupied the copper-deficient sites of Cu2-xS NCs, x could be controlled from 0.9 to less than 0.1. Consequently, the near-infrared (NIR) absorbance of Cu2-xS NC assemblies changes systematically with x. With increasing x, electrical conductivity increased and the Seebeck coefficient decreased systematically, leading to the maximal thermoelectric power factor from a film of Cu2-xS NCs at an optimal doping condition yielding x = 0.1. The physical characteristics of the Cu2-xS NC assemblies investigated herein will provide guidelines for exploiting this emerging class of nanocrystal system based on doping. |
| Databáze: | OpenAIRE |
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