Size‐Tunable Photothermal Germanium Nanocrystals

Abstract

Germanium nanocrystals (ncGe) have not received as much attention as silicon nanocrystals (ncSi). However, Ge has demonstrated superiority over Si nanomaterials in some applications. Examples include, high charge-discharge rate lithium-ion batteries, small band-gap opto-electronic devices, and photo-therapeutics. When stabilized in an oxide matrix (ncGe/GeO ), its high charge-retention has enabled non-volatile memories. It has also found utility as a high-capacity anode material for Li-ion batteries with impressive stability. Herein, we report an organic-free synthesis of size-controlled ncGe in a GeO matrix as well as freestanding ncGe, via the thermal disproportionation of GeO prepared from thermally induced dehydration of Ge(OH) . The photothermal effect of ncGe, quantified by Raman spectroscopy, is found to be size dependent and superior to ncSi. This advance suggests applications of ncGe in photothermal therapy, desalination, and catalysis.

2D Monoelemental Germanene Quantum Dots: Synthesis as Robust Photothermal Agents for Photonic Cancer Nanomedicine

“…[4] Due to their unique properties,including broad absorption, ultrahigh surface-to-volume ratio,t ractable synthesis,e ase of modification, potentially simple metabolism and degradation mechanisms,t heir applications as all-aspect-satisfactory PTAs are promising. [5b,6] Thewide absorption range of germanium from ultraviolet to NIR region [7] indicates that the synthesized 2D germanene may have ag reat chance to be ar obust PTA. [5b,6] Thewide absorption range of germanium from ultraviolet to NIR region [7] indicates that the synthesized 2D germanene may have ag reat chance to be ar obust PTA.…”

“…[7,10] Furthermore,g ermanium nanomaterials without 2D structure may compromise the PTAp erformance.W hile mechanical cleavage and physical vapor deposition methods have successfully been used to prepare 2D germanene, [5a,c,d, 11] the efficient manufacture of novel germanene nanostructures is still ac hallenge. [7,10] Furthermore,g ermanium nanomaterials without 2D structure may compromise the PTAp erformance.W hile mechanical cleavage and physical vapor deposition methods have successfully been used to prepare 2D germanene, [5a,c,d, 11] the efficient manufacture of novel germanene nanostructures is still ac hallenge.…”

“…[4] Germanene is ar ecently developed 2D monoelemental material [5] that shows unique advantages over the prototypical 2D Xenes,such as graphene and BP. [5b,6] Thewide absorption range of germanium from ultraviolet to NIR region [7] indicates that the synthesized 2D germanene may have ag reat chance to be ar obust PTA. Notably,g ermanium, as at race element in the human body,p lays important roles in human health.…”

“…Although different methods have been used to prepare germanium-based nanomaterials,h arsh reaction conditions (for example,high crystallization temperature) and chemicals (for example,n -butyllithium, sodium metal, metal hydrides, or sodium naphthenalide) are required to produce elemental germanium-based nanomaterials. [7,10] Furthermore,g ermanium nanomaterials without 2D structure may compromise the PTAp erformance.W hile mechanical cleavage and physical vapor deposition methods have successfully been used to prepare 2D germanene, [5a,c,d, 11] the efficient manufacture of novel germanene nanostructures is still ac hallenge.…”

Solid‐State Route for the Synthesis of Scalable, Luminescent Silicon and Germanium Nanocrystals

“…Solid‐state methods based on thermal processing of non‐stoichiometric Si and Ge oxides (i. e. SiO x and GeO x where 0<x<2) have gained tremendous attention due to the precise control over the NC size and optical properties . However, the processing temperatures often remain higher than 1000 °C for Si.…”