Synthesis of single-crystalline ZnO nanoflowers for a superhigh-sensitivity ultraviolet photodetector application.

The high-performance, low-cost and simple ultraviolet photodetectors are very promising in some applications. Here, single-crystalline zinc oxide (ZnO) nanoflowers were prepared by combining a facile hydrothermal method with post-annealing treatment, we built an ultraviolet photodetector with an active area of 0.36 cm2 using the as-prepared ZnO nanoflowers. The results showed that under 365 nm light illumination with a light intensity of 77 μW/cm2, the sensitivity, response time, decay time, responsivity and gain of the device were 19991.3 (−0.1 V), 16.4 s, 37.6 s, 9.0 A/W (5 V) and 30.6 (5 V), respectively, indicating that a ZnO nanoflowers UV photodetector with superhigh sensitivity was achieved. At a bias of 2 V, the photocurrent of the ZnO nanoflowers UV photodetector can be reproducibly switched from the 'ON' state to the 'OFF' state with a very stable state by periodically turning UV light (365 nm, 77 μW/cm2) on and off.▪ • The ZnO nanoflowers were prepared by combining a facile method. • The ZnO nanoflowers are single crystalline. • A low-cost ultraviolet photodetector with simple structure was fabricated. • The fabricated ultraviolet photodetector had a superhigh sensitivity of 19991.3. [ABSTRACT FROM AUTHOR]