Transparent capacitors based on nanolaminate Al_2O_3/TiO_2/Al_2O_3 with H_2O and O_3 as oxidizers

摘要

Transparent capacitors with nanolaminate Al_2O_3/TiO_2/Al_2O_3 (ATA) hybrid dielectrics have been prepared on quartz glass by atomic layer deposition. The maximal capacitance density of 14 fF/μm~2 at 1kHz was obtained. Moreover, an ultralow leakage current density of 2.1 × 10~(-9) A/cm~2 at 1V was realized by using O_3 as the oxidizer. Fowler-Nordheim tunneling is the main mechanism of the leakage current at high fields, while several conduction mechanisms coexist at low fields. The AlZnO/ATA/AlZnO transparent capacitors exhibit an average optical transmittance of more than 80% in the visible range, which serve as good candidates for integration in transparent circuits.