Direct white light emission from a rare-earth-free aluminium–boron–carbon–oxynitride phosphor

Abstract

White light-emitting diodes offer the possibility of efficient, safe, and reliable solid-state lighting, and thus have various applications. Reported white light-emitting phosphors usually contain expensive rare-earth metals and are generally prepared by high-energy processes (e.g., >1000 °C, H₂ and CO reduction atmospheres). These factors limit their applications. Therefore, preparing cost-effective white light-emitting phosphors from environmentally friendly processes is an important challenge. Herein, a direct white light-emitting aluminium–boron–carbon–oxynitride (AlBCNO) phosphor, which can be economically produced using low-energy methods (<900 °C, atmospheric conditions), is reported. To the best of our knowledge, this is the first reported rare-earth-free white light-emitting phosphor. AlBCNO emission spans the entire visible spectrum and its broad excitation spectrum is comparable to that of near-UV light-emitting diodes. Increasing the relative concentrations of B or Al in AlBCNO enables emission tuning to yellow or blue, respectively. These findings have implications for new methods of preparing white light-emitting phosphors.