The  paper of  the  month,  chosen  by  the Editor-in-Chief,  is  "Epitaxy and Structural, Electrical, and Optical Characterization of Pb₁₋ₓSnₓTe Semiconductor Layers Grown by MBE on CdTe/GaAs Hybrid Substrates"  by W. Wołkanowicz, P. Dziawa, M. Zięba, R. Minikayev, A. Sulich, E. Łusakowska, A. Reszka, K. Dybko, T. Andrearczyk, M. Szot, L. Kowalczyk, A. Witowski, J. Polaczyński, W. Zaleszczyk, T. Wojtowicz and T. Story;

DOI: 10.12693/APhysPolA.148.257

The paper is devoted to a study of Pb₁₋ₓSnₓTe, a IV-VI substitutional semiconductor alloy exhibiting excellent thermoelectric and optoelectronic properties in the infra-red region. The properties can be tuned by the tin content. An original novel approach to the MBE growth of Pb₁₋ₓSnₓTe layers on GaAs using CdTe/GaAs hybrid substrates is presented. Successful crystal growth in the full composition range, i.e. for all x was achieved. A significant reduction in strain-induced macroscopic cracking compared to layers grown without a buffer was found. Achieving high-quality Pb₁₋ₓSnₓTe layers on commercially available substrates is important for thermoelectric and optoelectronic applications. The paper should of interesting to people thinking about such applications. In addition, it has been shown in the paper that the material exhibits non-trivial topological properties, and therefore the paper should of interest to a broad range of physicists. 

The Editor-in-Chief