Optically Transparent Wood Substrate for Perovskite Solar Cells

Transparent wood is a candidate for use as an energy-saving building material due to its low density (ca. 1.2 g/cm 3 ), high optical transmittance (over 85% at 1 mm thickness), low thermal conductivity (0.23 W m -1 K -1 ), and good load-bearing performance with tough failure behavior (no shattering). High optical transmittance also makes transparent wood a candidate for optoelectronic devices. In this work, for the first time, perovskite solar cells processed at low temperature (<150 °C) were successfully assembled directly on transparent wood substrates. A power conversion efficiency up to 16.8% was obtained. The technologies demonstrated may pave the way for integration of solar cells with light transmitting wood building structures for energy-saving purposes.