Synthesis of BaZrS₃ and BaHfS₃ Chalcogenide Perovskite Films Using Single‐Phase Molecular Precursors at Moderate Temperatures

Abstract

Chalcogenide perovskites have garnered interest for applications in semiconductor devices due to their excellent predicted optoelectronic properties and stability. However, high synthesis temperatures have historically made these materials incompatible with the creation of photovoltaic devices. Here, we demonstrate the solution processed synthesis of luminescent BaZrS3 and BaHfS3 chalcogenide perovskite films using single‐phase molecular precursors at sulfurization temperatures of 575 °C and sulfurization times as short as one hour. These molecular precursor inks were synthesized using known carbon disulfide insertion chemistry to create Group 4 metal dithiocarbamates, and this chemistry was extended to create species, such as barium dithiocarboxylates, that have never been reported before. These findings, with added future research, have the potential to yield fully solution processed thin films of chalcogenide perovskites for various optoelectronic applications.

A selenium-based “alkahest”: reactive dissolutions of metals and metal compounds with n-alkylammonium polyselenide solutions

“…PL spectra were corrected with transfer functions as described previously. 39 X-ray fluorescence (XRF) was performed with a Fisher XAN 250 instrument that utilized a voltage of 50 kV, a silicon drift detector, a primary nickel filter, and helium as a flowing gas purge. For XRF measurements, the complexes were sealed in mylar packets under a nitrogen atmosphere.…”

Formation of Homoleptic Zirconium and Hafnium Dithiocarbamates via Insertion of CS2: Breaking Bonds and Taking Names

“…Previous reports from our groups have demonstrated the utility of these species for the synthesis of BaZrS 3 , a wellknown chalocogenide-rich perovskite in development for its photovoltaic properties. 6 To further demonstrate the broad utility of the Group IV dithiocarbamates, a solution-phase nanoparticle synthesis of ZrS 3 has been established. In this case, generation of this material is possible via the thermal decomposition of Zr(κ 2 -S 2 CNMeEt) 4 , generating ZrS 3 nanoribbons.…”

“…5 Using an alternative solution deposition approach, our groups have recently published a moderate-temperature synthetic route where BaMS 3 materials (M = Zr, Hf) were obtained at temperatures as low as 550 °C from commercially available starting materials, including Cp* 2 Ba, M(NMeEt) 4 or M(NEt 2 ) 4 (M = Zr, Hf), and CS 2 . 6,7 Mechanistic investigations on the formation of BaMS 3 using these materials supported that welldefined homoleptic CS 2 insertion products, including Zr and Hf dithiocarbamate derivatives, were intermediates in this process.…”

“…Gratifyingly, the ethyl−methyl compound, M-(NMeEt) 4 , struck the right balance between synthetic ease/ solubility with minimal residual carbon in the final material. 6,7 Based on the utility of these materials, our studies focused on an updated and improved synthesis for M(κ 2 -S 2 CNEt 2 ) 4 and M(κ 2 -S 2 CNEtMe) 4 (M = Zr, Hf) from CS 2 insertion into M(NMeEt) 4 and M(NEt 2 ) 4 (M = Zr, Hf), respectively. This method resulted in near quantitative yields, reduced side products, and facilitated a single-pot synthetic route compared to previous reported routes.…”

“…This method resulted in near quantitative yields, reduced side products, and facilitated a single-pot synthetic route compared to previous reported routes. 6,7 The higher yields and increased purity are necessary for making these molecules viable precursors for low-temperature syntheses of chalcogenide perovskite materials. Herein, we report this efficient synthetic technique along with the full characterization of these four species using multinuclear NMR spectroscopy, infrared spectroscopy, and X-ray crystallography.…”