1. Department of Applied Physics Aalto University ESPOO FIN‐02150 Finland
2. Research Institute of Wood Industry Chinese Academy of Forestry Xiangshan Road Beijing 100091 China
3. Department of Bioproducts and Biosystems Aalto University Espoo FIN‐02150 Finland
4. Faculty of Engineering and Natural Sciences Tampere University Tampere FI‐33101 Finland
5. Microelectronics Research Unit Faculty of Information Technology and Electrical Engineering University of Oulu Oulu FIN‐90014 Finland
6. Department of Materials Science Advanced Coating Research Center of Ministry of Education of China Fudan University Shanghai 200433 China