White light emission from amorphous silicon‐oxycarbide materials

This paper reports white photoluminescence (PL) from silicon-oxycarbide materials. These are oxidized mesoporous carbon silica (MPCS) and thermally treated rice husk. The PL intensities were strong enough to be detected by the naked eye in daylight under ultraviolet light excitation at room temperature. We investigated the structure, composition, and bonding state of fabricated silicon-oxycarbide materials and found the commonality between the oxidized MPCS and the thermally treated rice husk. Both of them (i) were composed of silica and small amount of carbon, (ii) have porous structure and large surface area over 100 m2/g, and (iii) have a broad infrared absorption band at around 1100 cm−1 related to the strained silica. The origins of white PL are discussed by taking account of the commonality.