High-throughput investigation of second harmonic generation enhancement in indium tin oxide films: Effects of Sn doping

Abstract

The doping effect of the Sn atom in indium tin oxide (ITO) plays a crucial role in influencing the epsilon-near-zero (ENZ) behaviors and the related nonlinear optical properties. A ternary (In1−xSnx)2O3 film is fabricated by high-throughput magnetron sputtering technique. The relationship between Sn doping and second harmonic generation (SHG) enhancement is systematically interpreted through comprehensive characterization of structural and optical properties. Significantly, clear microstructural changes associated with different levels of Sn doping are identified by x-ray diffraction and Raman spectroscopy. These changes directly contribute to shifts in the ENZ wavelength (λENZ). The results indicate that the optimal region for SHG enhancement lies within 7.3–10.6 at. % Sn doping. Moreover, it is demonstrated that λENZ can be adjusted by manipulating the formation of electrically inactive defect clusters via Sn substitution at the 24d sites. This study not only provides valuable insight into the mechanism linking Sn doping and SHG enhancement of ITO but also exemplifies the high-throughput exploration of optical functional materials.