[20p-B204-1~13] 6.3 Oxide electronics

▼ [20p-B204-4] Deep-UV transparent conducting SrSnO₃ freestanding sheet using Al₂O₃ protection layer

〇(D)Lizhikun Gong¹, Mian Wei¹, Rui Yu¹, Hiromichi Ohta², Katayama Tsukasa^2,3 (1.IST, Hokkaido Univ., 2.RIES, Hokkaido Univ., 3.JST-PRESTO)

Keywords:wide bandgap, Conducting film

Flexible and functional perovskite oxide sheets with high orientation and crystallization are the key step forward to next-generation devices. One promising synthesis method is a lift-off and transfer method by etching a water-soluble sacrificial layer between the oxide film and substrate. This method has many advantages, such as easily adds flexibility to perovskite oxides and allows the reuse of expensive single-crystal substrates. However, there is still one crucial problem; that is the difficulty to suppress cracks during the lift-off process. In this study, we demonstrated that this problem can be solved by simply adding an amorphous Al₂O₃ capping layer on the oxide sheet.
Through this method, a 5 × 5 mm crack-free La-doped SrSnO₃ (LSSO) flexible sheet was obtained on PET substrate, whereas the sheets broke into pieces without covered by the capping layer. The freestanding LSSO flexible sheets are able to be rolled and spread repeatedly using mechanical forces, such as airflow generated by washing ear ball and/or manual vibration, demonstrating the excellent flexibility and elasticity of the sheet. (Fig. 1). In addition, the sheet exhibited coexistence of high electrical conductivity (~1600 S cm⁻¹) and wide bandgap (~4.4 eV) at room temperature, indicating the great potential of the LSSO sheets as wide-bandgap transparent electrodes for deep ultraviolet-related devices.