3:15 PM - 3:30 PM
▼ [16p-Z24-8] Flexible, Active-Matrix Image Sensor Array Integrated with ZnIn2S4 Nanosheets and InGaZnO Transistor
Keywords:flexible, imaging, optical sensor
Combining conventional optical sensors and flexible electronic technology makes it possible to detect light distribution from the curved surfaces. However, the flexible image sensor's optimal structures and materials are still under development for practical applications. To propose the new material and structure, we introduced a large-scale active matrix-based flexible image sensor array consisted of InGaZnO transistor and stacked ZnIn2S4 (ZIS) nanosheets as the optical sensing material.
First, ZnIn2S4 nanosheet film, formed by the solution-based process, was characterized to confirm photosensitivity. The on/off current ratio under a light intensity of 10.4 mW/cm2 is 17.2 with a relatively short response (100 ms) and recovery time (300 ms). Moreover, the ZIS-based optical sensor shows good stability under multiple cycle test.
Besides, the flexible InGaZnO transistors for the active matrix circuitry were also studied. The representative field-effect mobility is ~7 cm2/Vs and ION /IOFF is >105 at VDS = 3 V. Importantly, it is confirmed that the transistors are formed with good uniformity on a polyimide film.
Finally, by utilizing the excellent optical properties of ZIS and uniform flexible InGaZnO transistor, a large scale (13×4 array) active-matrix image sensor array was fabricated. The integrated device maintains good photosensitivity and shows mechanical stability after multiple bending cycles. As a result, we could map the light distribution under flat and bending conditions successfully.
In summary, we demonstrate a flexible optical imager using the photosensitive ZnIn2S4 nanosheets with InGaZnO transistors after confirming excellent optical behaviors and mechanical stability. These results indicate that this flexible image sensor array may be a high potential to map the light distribution on a curved surface.
First, ZnIn2S4 nanosheet film, formed by the solution-based process, was characterized to confirm photosensitivity. The on/off current ratio under a light intensity of 10.4 mW/cm2 is 17.2 with a relatively short response (100 ms) and recovery time (300 ms). Moreover, the ZIS-based optical sensor shows good stability under multiple cycle test.
Besides, the flexible InGaZnO transistors for the active matrix circuitry were also studied. The representative field-effect mobility is ~7 cm2/Vs and ION /IOFF is >105 at VDS = 3 V. Importantly, it is confirmed that the transistors are formed with good uniformity on a polyimide film.
Finally, by utilizing the excellent optical properties of ZIS and uniform flexible InGaZnO transistor, a large scale (13×4 array) active-matrix image sensor array was fabricated. The integrated device maintains good photosensitivity and shows mechanical stability after multiple bending cycles. As a result, we could map the light distribution under flat and bending conditions successfully.
In summary, we demonstrate a flexible optical imager using the photosensitive ZnIn2S4 nanosheets with InGaZnO transistors after confirming excellent optical behaviors and mechanical stability. These results indicate that this flexible image sensor array may be a high potential to map the light distribution on a curved surface.