Highly luminescent Gd2O2S:Er3+,Yb3+ upconversion microcrystals obtained by a time- and energy-saving microwave-assisted solid-state synthesis

Er3+-doped and Er3+,Yb3+-co-doped Gd2O2S are one of the most efficient upconversion (UC) materials available to date. However, preparing lanthanide oxysulfides can be challenging as it requires several hours heating at>1000 °C in high power furnaces. Nonetheless, designing a new synthesis technology for UC materials, should consider that these systems suffer from defect quenching, responsible significant optical energy losses. In this work, microwave-assisted solid-state (MASS) was explored an alternative synthesize class using two different starting compounds – oxides (Ln2O3) hydroxycarbonates (Ln(OH)CO3), where Ln3+: Gd, Er, Yb. Different Er3+,Yb3+ concentrations were investigated, Er3+(5%),Yb3+(5%) Er3+(1%),Yb3+(10%) shown give intense output comparable commercially materials. Using Ln(OH)CO3 instead more common Ln2O3 MASS contributed higher efficiencies homogeneous Er3+ especially Yb3+ distribution through lattice verified by luminescence lifetime measurements. These high-quality prepared simple two-step 50 min domestic microwave oven, leading remarkable decrease 79% processing time 93% consumption, making method suitable methodology performance