Quenched, nanocrystalline In4Sn3O12 high temperature phase for gas sensing applications

Flame spray pyrolysis (FSP) allowed quenching the high temperature phase In4Sn3O12 in the form of highly single crystalline particles of about 6 nm. These nanoparticles were in situ deposited to form stable porous films on interdigitated electrodes. The resulting gas sensors were tested for formaldehyde sensing in the low ppb range. Comparing systematic composition of the In–Sn–oxide system ranging from pure In2O3, In1.9Sn0.1O3 (ITO), In4Sn3O12 and SnO2 with their corresponding mixtures showed by far the best sensor performance at 250 °C for 43% of (Sn/(Sn + In), corresponding to the In4Sn3O12 phase. The sensors tested using this phase outperformed state of the art metal oxide devices. The In4Sn3O12 phase was stable beyond the operation time and temperature used here, demonstrating its enormous but largely undiscovered potential in the future.