Institute of High Pressure Physics

Two important topics in semiconductor physics are under intensive study by Unipress staff. First is related to growth mechanism of the semiconductor material. In the paper by S. Krukowski, K. Sakowski, P. Strak, P. Kempisty, J. Piechota, I. Grzegory entitled "Macrosteps dynamics and the growth of crystals and epitaxial layers" (Progr. Cryst. Growth. Char. Mater. 68, 100581, 2022), by NL3 theoretical group, the mechanism of emergence of multi- and macrosteps is explained by the theoretical model. In particular, the single-step mode of growth in the macrostep presence is presented. This pattern is crucial for understanding of mechanism of macrostep crystal growth mode.

Another aspect is the study of new polarization doping method for AlGaN heterostructures. In the paper by A. Ahmad, P. Strak, P. Kempisty, K. Sakowski, J. Piechota, Y. Kangawa, I. Grzegory, M. Leszczynski, Z. R. Zytkiewicz, G. Muziol, E. Monroy, A. Kaminska, S. Krukowski entitled "Polarization doping — Ab initio verification of the concept: Charge conservation and nonlocality" (J. Appl. Phys. 132, 064301, 2022), developed by NL3 theoretical group in cooperation with NL12, NL14, Univ. Grenoble-Alpes, Institute of Physics and Kyushu University scientists. In this theoretical study based on numerical simulation, existence of the polarization charge in variable-content layers were demonstrated and emergence of the mobile charge is presented. In particular, the device-size compensation is discussed, which is an important aspect in design of AlGaN UV heterostructures.