However, it was found that applying an auxiliary pressure of 6 bar (Ar/O2, 80:20 ml min -1 ) and incorporating 5 % excess of In2O3 effectively minimized In2O3 loss, which has a relatively low evaporation temperature of 1150 °C at ambient pressure . As a result of this approach, the molten zone was successfully stabilized (see Figure S 4 and Figure S 5). To maximize the size of the grown single crystals and minimize growth time to reduce evaporation, the growth rate was stabilised at 4 mm h -1 .