| 초록 |
This study shows that the deep-level defect states in sol-gel-derived ZnO can be efficiently restored by facile sulfur doping chemistry, wherein the +2 charged oxygen vacancies are filled with the S2− ions. The synergetic effects of such defect-restored ZnO electron selective layers for organic Schottky photodiodes are demonstrated. The decreased chemical defects and thus reduced mid-gap states enable to not only enlarge the effective built-in potential but also increase the Schottky energy barrier between ITO/ZnO cathode and semiconducting polymer. As a result, the demonstrated simple-structure blue-selective organic Schottky photodiode renders near-ideal diode operation with an ideality factor of 1.18, a noise equivalent power of 1.25 × 10−14 W Hz−1/2, and a high peak detectivity of 2.4 × 1013 Jones. In addition, the chemical robustness of fabricated devices enables exceptional device stability against ambient condition as well as device-to-device reproducibility. Therefore, this work opens the possibility of utilizing low-temperature sol-gel-derived ZnO in realizing high-performance, stable, and reliable organic photodiodes that could be employed in the design of practical image sensors. |
