This article is devoted to the comparison of the influence of the piezoelectric matrix properties on the magnitude of the resulting charge when a thin piezoelectric membrane of circular cross section, made from aluminium gallium nitride (Al-GaN), is loaded. The size of change of the electric charge was determined by the numerical analysis and the by the change of the properties of the piezoelectric matrix. The matrix constants were obtained from various sources introduced in world databases.
 A. D. Bykhovski, V. V. Kaminski, M. S. Shur, Q. C. Chen, and M. A. Khan, Appl. Phys. Lett.1996 (68), 818.
 G. D. O’Clock, M. T. Duffy. Acoustic surface wave properties of epitaxially grown aluminum nitride and gallium nitride on sapphire. Appl. Phys. Lett.1973 (23), No. 2, 55.
 C. Bowen, D. Allsopp, R. Stevens, P. Shields, W. Wang. Modelling and designing GaN piezeoelectric MEMS. In: Second International Conference on Multi-Material Micro Manufacture, Grenoble. 2006.
 J.C. Freeman. Basic Equations for the Modeling of Gallium Nitride (GaN) High Electron Mobility Transistors. 2003, NASA/TM-2003-211983.
 P. Staňák, J. Sládek, V. Sládek. Analysis of piezoelectric semiconducting solids by meshless method, Journal of Mechanical Engineering - Strojnícky časopis2015 (65), No. 1, 77 – 92.
 T. Kováč, F. Horvát, M. Čekan, B. Hučko, M. Szarvas, J. Dzuba, G. Vanko. Numerical solution of aluminum galium nitride membrane in finite element analysis. 15th Conference on Applied Mathematics APLIMAT 2016 Proceedings, Bratislava 2016, 2016, 700 - 710.
 J. Dzuba, G. Vanko, O. Babchenko, T. Lalinský, F. Horvát, M. Szarvas, T. Kováč, B. Hučko. Strain induced response of AlGaN/GaN high electron mobility transistor located on cantilever and membrane. ASDAM 2016 - Conference Proceedings, 11th International Conference on Advanced Semiconductor Devices and Microsystems, art. no. 7805936, 2017, 227 - 230.