Solution‐Phase Conversion of Bulk Metal Oxides to Metal Chalcogenides Using a Simple Thiol–Amine Solvent Mixture

Abstract

A thiol-amine solvent mixture is used to dissolve ten inexpensive bulk oxides (Cu2O, ZnO, GeO2, As2O3, Ag2O, CdO, SnO, Sb2O3, PbO, and Bi2O3) under ambient conditions. Dissolved oxides can be converted to the corresponding sulfides using the thiol as the sulfur source, while selenides and tellurides can be accessed upon mixing with a stoichiometric amount of dissolved selenium or tellurium. The practicality of this method is illustrated by solution depositing Sb2Se3 thin films from compound inks of dissolved Sb2O3 and selenium that give high photoelectrochemical current response. The direct band gap of the resulting material can be tuned from 1.2-1.6 eV by modulating the ink formulation to give compositionally controlled Sb2Se(3-x)S(x) alloys.

High-performance thermoelectric silver selenide thin films cation exchanged from a copper selenide template

“…48,49,53 To form a thin-lm NC template, we adopted a method developed by Webber et al which demonstrated that bulk copper chalcogenides such as Cu 2 Se, Cu 2 Te and Cu 2 S can be dissolved in a thiol-amine solution mixture and be cast as thin lms on substrates. 45,51,54,55 However, bulk Ag 2 Se powder fails to do so at ambient conditions (see ESI, Fig. S3 †).…”

“…S3 †). 45,50 To overcome this issue, we use an innovative combination of thiol-amine dissolution and CE techniques to realize a simple pathway to obtaining high-performance Ag 2 Se thin lms. We rationalize the CE using a mix of thermodynamic and kinetic parameters.…”

“…The most convincing hypothesis involves the formation of the thiolatothiometallate anions counterbalanced by the enH + cations in the chalcogenide/en/edtH 2 system but this does not directly describe why some chalcogenides can be dissolved and some cannot. [44][45][46] An alternative approach that has been typically used in the semiconductor NC community is to take advantage of established protocols to synthesize common chalcogenide NCs and use cation exchange (CE) as a facile method to convert it into a high value product that cannot be synthesized directly. 47 CE has been demonstrated to be a versatile, efficient and convenient tool to expand the library of attainable materials with new and unique material phases, shapes and compositions.…”

Earth abundant CuSbS2 thin films solution processed from thiol–amine mixtures

“…To overcome this challenge, we first reported in 2013 a binary solvent system comprised of a short chain alkanethiol and ethylenediamine (termed an "alkahest"), which we have since demonstrated to have appreciable solvent power to rapidly dissolve numerous bulk materials under ambient conditions. [7][8][9][10][11][12] The resulting inks can be readily solution processed because of the appropriate solvent volatility, and upon thermal annealing at low temperatures, give phase--pure semiconductor thin films. For example, this thiol--amine solvent system has been used by Arnou et al, Zhao et al, and Zhang et al to solution process thin films of multinary semiconductors, such as CIS, CIGS, and CZTS.…”

Recent Progress on Cu2BaSn(SxSe1–x)4: From Material to Solar Cell Applications

“…[88] The S peak from the surface (SO 3,4 ) 2À species was observed, indicating the oxidation of Cu 2 BaSnS 4 surface. [89] After the surface treatment with argon ions, the surface oxidation was removed. The authors successfully obtained single-phase Cu 2 BaSn(S x Se 1-x ) 4 films with bandgaps of 1.86-1.56 eV via simply modification of the initial Se precursor contents in the inks, showing the possibility of preparing single-phase Cu 2 BaSn(S x Se 1-x ) 4 films with tunable bandgaps by this alkahest method.…”