Simultaneous enhancement of electromagnetic interference shielding and infrared transmittance based on SnO2 thin films

Mn-doped SnO2 thin films were fabricated to enhance two conflicting properties of the electromagnetic interference (EMI) shielding effectiveness and the infrared (IR) wavelength ranges. As a magnetic element, manganese (Mn) was doped into the SnO2 thin films at an over-doping level of 300 mM to increase its magnetic permeability. As the molar content of Mn increases, the preferred growth plane of the SnO2 thin films changes from (200) to (115) planes. Although all SnO2 thin films showed diamagnetic properties due to the strong diamagnetism of the substrate and SnO2, the magnetic susceptibility of the Mn-doped SnO2 films slightly decreased with increasing the Mn content from 0 to 60 mM, while it increased again with the doping content above it. As the Mn doping content increased from 0 to 150 mM, the sheet resistance of SnO2 films continuously increased from 98 to 128 Ω/sq. As the Mn content increases from 30 to 120 mM, the IR transmittance at 4 μm increases from 37 to 47