Color control of white photoluminescence from carbon-incorporated silicon oxide

Abstract

Color control of the white photoluminescence (PL) from carbon-incorporated silicon oxide is demonstrated. The carbon-incorporated silicon oxide was fabricated by carbonization of porous silicon in acetylene flow (at 650 and 850 °C) followed by wet oxidation (at 650 and 800 °C). It was shown that PL color can be controlled in the range of blue-white and yellow-white by selecting the porosity of starting porous silicon as well as the carbonization and oxidation temperatures. Low-temperature oxidation resulted in bluish light emission in lower porosity series, while high-temperature oxidation promoted yellow-white light emission. The maximal integral intensity of PL was observed after oxidation at 800 °C. It was shown that white PL from carbon-incorporated silicon oxide has blue and yellow-white PL bands originating from different light-emitting centers. The origin of blue PL is attributed to defects in silicon dioxide. Some trap levels at the interface of the carbon clusters and silicon oxide are suggested to be the origin of the yellow-white light emission.