Syntheses, structures, and optical properties of the indium/germanium selenides Cs4In8GeSe16, CsInSe2, and CsInGeSe4

• The solid-state In/Ge selenides Cs4In8GeSe16, CsInSe2, and CsInGeSe4 have been synthesized.
• Both Cs4In8GeSe16 and CsInGeSe4 display In/Ge disorder.
• Cs4In8GeSe16 and CsInGeSe4 have band gaps of 2.20 eV and 2.32 eV, respectively.

The three solid-state indium/germanium selenides Cs4In8GeSe16, CsInSe2, and CsInGeSe4 have been synthesized at 1173 K. The structure of Cs4In8GeSe16 is a three-dimensional framework whereas those of CsInSe2 and CsInGeSe4 comprise sheets separated by Cs cations. Both Cs4In8GeSe16 and CsInGeSe4 display In/Ge disorder. From optical absorption measurements these compounds have band gaps of 2.20 and 2.32 eV, respectively. All three compounds are charge balanced.

Structure of Cs4In8GeSe16Figure optionsDownload as PowerPoint slide