1. Laboratory of Semiconductor Materials, Institute of Materials, School of Engineering, École Polytechnique Fédérale de Lausanne, Route Cantonale, 1015 Lausanne, Switzerland
2. Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
3. Institute of Physics, School of Basic Sciences, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland