K₂Hg₂Se₃: Large-Scale Synthesis of a Photoconductor Material Prototype with a Columnar Polyanionic Substructure

Abstract

K 2 Hg 2 Se 3 , a new photoconducting material with a direct band gap around 1.4 eV, was obtained in nearly quantitative yields and large scale (50 g per batch) by means of solvothermal treatment of a corresponding solid. The compound comprises covalently linked selenidomercurate columns that accommodate potassium counterions. Composition and structure allow for a specific combination of optoelectronic, photophysical, and thermoelectric properties, which initiates a systematic material development within this family of compounds.T he search for innovative materials for electronic applications is an enormous stimulus for contemporary chemical and physical research activities. A large portion of according materials are found within oxides and chalcogenides of fourth and fifth period metals.

Solvothermal Reactions in and with Nitriles

“…Such reaction conditions, which had been identified to be suitable for the generation of ternary metalate species such as K 2 Hg 2 Se 3 or K 4 [PbSe 4 ]·en·NH 3 (en = ethane-1,2-diamine) in amines as solvents, were now transferred to nitriles. [18] In a reaction of "KPbTe" with water-free NiCl 2 , we did not obtain a quaternary phase, as initially planned, but isolated small amounts of the acetonitrile tetramer as a ligand to Ni 2+ cations in a dinuclear complex, [(C 8 H 12 N 4 )NiCl(μ-Cl)] 2 (1; Figure 1). …”

(C4C1Im)6[Hg7Se10]: The Salt of a Molecular Selenido Mercurate Anion Obtained from Ionic Liquids

“…Ionothermal treatment of the ternary selenido mercurate K 2 [Hg 2 Se 3 ], which bears a three‐dimensional anionic substructure, in (C 4 C 1 Im)[BF 4 ] (C 4 C 1 Im = 1‐butyl‐3‐methylimidazolium) in the presence of en (1 %) at 80 °C for 4 d yields the compound (C 4 C 1 Im) 6 [Hg 7 Se 10 ] ( 1 ) (Scheme ). Crystals of the salt are obtained in approximately 10 % yield besides unreacted starting material over the course of several months at room temperature.…”

Formation of Crystalline Telluridomercurates from Ionic Liquids near Room Temperature

“…Na 2 [Hg 3 E 4 ], E = S, Se),[15f], and 3D frameworks (e.g. K 2 [Hg 2 Se 3 ], A 2 [Hg 6 E 7 ], A/E = K/S, K/Se, Rb/S, Rb/Se, Cs/S, Cs/Se),[10b], [15f], , [33a], , all of which are based on either linear, trigonal‐planar, or tetrahedral [Hg E n ] ( n = 2–4) building units.…”

“…A particular focus in the search for novel chalcogen compounds is put on heavy metal chalcogenides and related chalcogenidometalates, as they exhibit specific opto‐electronic and thermoelectric properties, which can be adjusted and fine‐tuned by corresponding choice of the elements and the structure motifs within the compounds …”