Chloride and Indium‐Chloride‐Complex Inorganic Ligands for Efficient Stabilization of Nanocrystals in Solution and Doping of Nanocrystal Solids

Abstract

Here, the surface functionalization of CdSe and CdSe/CdS core/shell nanocrystals (NCs) with compact chloride and indium-chloride-complex ligands is reported. The ligands provide not only short interparticle distances but additionally control doping and passivation of surface trap states, leading to enhanced electronic coupling in NC-based arrays. The solids based on these NCs show an excellent electronic transport behavior after heat treatment at the relatively low temperature of 190 degrees C. Indeed, the indium-chlorido-capped 4.5 nm CdSe NC based thin-film field-effect transistor reaches a saturation mobility of = 4.1 cm(2) (V s)(-1) accompanied by a low hysteresis, while retaining the typical features of strongly quantum confined semiconductor NCs. The capping with chloride ions preserves the high photoluminescence quantum yield (approximate to 66%) of CdSe/CdS core/shell NCs even when the CdS shell is relatively thin (six monolayers). The simplicity of the chemical incorporation of chlorine and indium species via solution ligand exchange, the efficient electronic passivation of the NC surface, as well as their high stability as dispersions make these materials especially attractive for wide-area solution-processable fabrication of NC-based devices

Modern Inorganic Aerogels

“…[71,72] In this,t he initial organic ligands were replaced by purely inorganic ones. [73] Theresulting structures are especially interesting for electronic applications because the particles are not separated by bulky organic ligands,hence their conductivity is improved. Besides these materials are also promising candidates for catalytic applications because of their clean surfaces.…”

Structure and phase behavior of polymer-linked colloidal gels

“…25 This challenge motivated some of us to study an alternative route to equilibrium gelation that controls the extent of bonding between the (primary) colloids using a (secondary) linking agent. 26 Many examples of such linking systems have been described, including colloid-polymer mixtures, [27][28][29][30][31] mixtures of oppositely charged colloids, 32,33 ion-linked functionalized nanocrystals, [34][35][36][37] DNA-linked nanoparticles, 38,39 and DNA nanostar mixtures. [40][41][42] The degree of bonding between the colloids can be restricted by appropriately tuning the amount of linker added.…”

Emerging Hierarchical Aerogels: Self‐Assembly of Metal and Semiconductor Nanocrystals

“…The replacement of the bulky organic ligands with tiny inorganic species in the NC building blocks with their subsequent assembly in macroscopic architectures seems to be a powerful toolbox to address these challenges. The diversity of inorganic species showing high binding affinity to the NC surface is astonishing and includes nowadays metal chalcogenide complexes, pseudohalides, chalcogenides, halogenidometallates, halides, oxometallates and polyoxometallates, and composition‐matched chalcogenidometallate complexes . The organic‐to‐inorganic ligand exchange usually proceeds completely via the formation of electrostatically stabilized NCs.…”