1. Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 84104 Bratislava, Slovakia
2. Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava, 84248 Bratislava, Slovakia
3. HUN-REN Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary
4. Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy
5. CNRS, CRHEA, Université Côte d’Azur, 06560 Valbonne, France