Characterization of flexible dilute nitride InSbN thin films and exploratory study for epidermal optoelectronics

Flexible devices have recently been actively investigated for various purposes. Sb-based materials particularly attractive for medical applications. We grew InSb and dilute nitride InSbN thin films on polyimide (PI) films and on quartz substrates by reactive radio frequency magnetron sputtering. By comparing the properties of thin films grown on PI films with those on quartz substrates, we revealed that InSb/PI contains large amount of native defects which originate from Sb clusters and Sb vacancies (VSb). Although the properties of the thin films grown on quartz substrates did not improve by nitridation, dilute nitride InSbN/PI showed superior properties to InSb/PI. These changes in thin film properties suggest that nitridation generates the substitution of VSb for N and the suppression of native defect formation. Consequently, dilute nitride InSbN/PI is potentially useful in electronic device applications. Furthermore, we evaluated the skin absorption of dilute nitride InSbN/PI. As a result, both In and Sb hardly permeated and were retained inside the skin. We conclude that the flexible dilute nitride InSbN/PI can be applied to epidermal optoelectronics.