%0 Journal Article
%A Samanta, Debabrata
%A Mukherjee, Suvashree
%A Kumar Mishra, Asish
%A Giri, Bhagyashri
%A Pratap Chaudhary, Sonu
%A Glazyrin, Konstantin
%A Bhattacharyya, Sayan
%A Dev Mukherjee, Goutam
%T Pressure-induced electronic transition in vacancy-ordered halide double perovskite Cs<sub>2</sub>TeBr<sub>6</sub> 
%J Journal of applied physics
%V 138
%N 3
%@ 0021-8979
%C Melville, NY
%I American Inst. of Physics
%M PUBDB-2025-04494
%P 035902
%D 2025
%X We report high-pressure x-ray diffraction, Raman scattering, photoluminescence, and absorption measurements on vacancy-ordered halide double perovskite ⁠Cs<sub>2</sub>TeBr<sub>6</sub>. An electronic transition becomes apparent at around 2.3 GPa, characterized by anomalous behavior in the normalized pressure as a function of the Eulerian strain, a broad minimum in Raman linewidth, and a slope change in the linear pressure variation of a Raman mode frequency. The large compressibility and the observed anomalies in Raman scattering suggest that the material is soft and exhibits a strong electron–phonon coupling. The broad emission below the bandgap is attributed to the recombination of self-trapped excitons. The  crystal, consisting of undistorted octahedra, exhibits substantial emission enhancement and bandgap narrowing under pressure. The electronic transition is further supported by the observed emission maximum and a small kink in the pressure variation of the bandgap at around 2.3 GPa. 
%F PUB:(DE-HGF)16
%9 Journal Article
%R 10.1063/5.0273331
%U https://bib-pubdb1.desy.de/record/639400