Dr. Cecilia Guillén is a Senior Researcher at the Department of Energy at CIEMAT, a Spanish public research center. She received her PhD in Applied Physics from the Autonomous University of Madrid in 1992. Since then, she has participated in 30 national and international R&D projects, all of them aimed at the study of photoactive materials, preparation processes and their scaling for the fabrication of thin-film devices. The work carried out is reflected in 150 publications in indexed journals, 119 publications in specialized conference proceedings and 11 book chapters. She has directed 6 Doctoral Theses, being co-author of 3 national and European patents. She has also participated in the development of prototypes and pilot plants applicable to the preparation of thin-film semiconductors through evaporation and sputtering processes.