1. Department of Civil, Environmental and Mechanical Engineering, University of Trento, Trento 38123, TN, Italy
2. Solar Energy Research Institute, the National University of Malaysia (SERI-UKM), 43600 Bangi, Selangor, Malaysia
3. School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, U.K.
4. Department of Materials Science, University of Milano-Bicocca, Milan 20125, MI, Italy