TY - JOUR

T1 - A Versatile Route to Assemble Semiconductor Nanoparticles into Functional Aerogels by Means of Trivalent Cations

AU - Zámbó, Dániel

AU - Schlosser, Anja

AU - Rusch, Pascal

AU - Lübkemann, Franziska

AU - Koch, Julian

AU - Pfnür, Herbert

AU - Bigall, Nadja C

N1 - Funding Information: The authors would like to acknowledge the financial support of the German Federal Ministry of Education and Research (BMBF) within the framework of the program NanoMatFutur, support code 03X5525. Furthermore, the project leading to these results has in part received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement 714429). In addition, this work was funded by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) under Germany's excellence strategy within the cluster of excellence PhoenixD (EXC 2122, project ID 390833453) and the grant BI 1708/4‐1. A.S. is thankful for financial support from the Hannover School for Nanotechnology (hsn). The authors moreover thank Armin Feldhoff and Jürgen Caro for providing the SEM facility, and the LNQE for providing the TEM.

PY - 2020/4/23

Y1 - 2020/4/23

N2 - 3D nanoparticle assemblies offer a unique platform to enhance and extend the functionality and optical/electrical properties of individual nanoparticles. Especially, a self-supported, voluminous, and porous macroscopic material built up from interconnected semiconductor nanoparticles provides new possibilities in the field of sensing, optoelectronics, and photovoltaics. Herein, a method is demonstrated for assembling semiconductor nanoparticle systems containing building blocks possessing different composition, size, shape, and surface ligands. The method is based on the controlled destabilization of the particles triggered by trivalent cations (Y3+ , Yb3+ , and Al3+ ). The effect of the cations is investigated via X-ray photoelectron spectroscopy. The macroscopic, self-supported aerogels consist of the hyperbranched network of interconnected CdSe/CdS dot-in-rods, or CdSe/CdS as well as CdSe/CdTe core-crown nanoplatelets is used to demonstrate the versatility of the procedure. The non-oxidative assembly method takes place at room temperature without thermal activation in several hours and preserves the shape and the fluorescence of the building blocks. The assembled nanoparticle network provides longer exciton lifetimes with retained photoluminescence quantum yields, that make these nanostructured materials a perfect platform for novel multifunctional 3D networks in sensing. Various sets of photoelectrochemical measurements on the interconnected semiconductor nanorod structures also reveal the enhanced charge carrier separation.

AB - 3D nanoparticle assemblies offer a unique platform to enhance and extend the functionality and optical/electrical properties of individual nanoparticles. Especially, a self-supported, voluminous, and porous macroscopic material built up from interconnected semiconductor nanoparticles provides new possibilities in the field of sensing, optoelectronics, and photovoltaics. Herein, a method is demonstrated for assembling semiconductor nanoparticle systems containing building blocks possessing different composition, size, shape, and surface ligands. The method is based on the controlled destabilization of the particles triggered by trivalent cations (Y3+ , Yb3+ , and Al3+ ). The effect of the cations is investigated via X-ray photoelectron spectroscopy. The macroscopic, self-supported aerogels consist of the hyperbranched network of interconnected CdSe/CdS dot-in-rods, or CdSe/CdS as well as CdSe/CdTe core-crown nanoplatelets is used to demonstrate the versatility of the procedure. The non-oxidative assembly method takes place at room temperature without thermal activation in several hours and preserves the shape and the fluorescence of the building blocks. The assembled nanoparticle network provides longer exciton lifetimes with retained photoluminescence quantum yields, that make these nanostructured materials a perfect platform for novel multifunctional 3D networks in sensing. Various sets of photoelectrochemical measurements on the interconnected semiconductor nanorod structures also reveal the enhanced charge carrier separation.

KW - functional aerogels

KW - multifunctional 3D networks

KW - nanocrystals

KW - photoelectrochemical sensing

KW - semiconductor nanoparticles

KW - solvogels

KW - trivalent cations

UR - http://www.scopus.com/inward/record.url?scp=85081755330&partnerID=8YFLogxK

U2 - 10.1002/smll.201906934

DO - 10.1002/smll.201906934

M3 - Article

C2 - 32162787

VL - 16

JO - Small

JF - Small

SN - 1613-6810

IS - 16

M1 - 1906934

ER -