Tailoring the free carrier and optoelectric properties of indium tin oxide film via quasi-continuous-wave laser annealing

In this study, a 1064-nm quasi-continuous-wave laser was employed to anneal the indium tin oxide (ITO) films, thereby prominently prompting transparency in the near-infrared region with insignificant variation in resistivity. The decrease in carrier density due to laser annealing contributed to the improvement in transparency. Interestingly, the depth-resolved X-ray photoelectron spectroscopy distinguishes between two different mechanisms for tailoring the properties of the free carriers. Tin oxide reduction in the oxygen-deficient zone of the ITO films at a depth of approximately more than 80 nm was more significant than that in the oxygen-rich zone within the top 80-nm thin layer. In addition, the elimination of oxygen vacancies in the oxygen-rich environments did not indicate apparent advantage when compared with that in the oxygen-deficient environments owing to the oxygen supplied during the tin oxide reduction process. These results provide an alternative laser annealing technologies for tailoring the properties of the free carriers and elucidating the fundamental mechanisms in oxygen-rich and oxygen-deficient environments in an annealing process.

Automated summary

In this study, a 1064-nm quasi-continuous-wave laser was used to anneal ITO films, improving transparency in the near-infrared region while minimizing changes in resistivity by reducing carrier density. Results showed that tin oxide reduction in the oxygen-deficient region of the ITO film at depths greater than 80 nm was more significant than in the oxygen-rich region within the top 80-nm thin layer. Additionally, eliminating oxygen vacancies in oxygen-rich environments did not provide a clear advantage compared to oxygen-deficient environments due to oxygen supplied during tin oxide reduction.