Dual-band ultraviolet photodetectors comprising nanostructured MgZnO on ZnO films

To extend the wavelength sensing limitation, dual-band ultraviolet photodetectors (UV-PDs) were studied. The ZnO/MgZnO dual-band UV-PDs were constructed by stacking MgZnO nanorods on ZnO films. The wide ultraviolet wavelength from 250 to 360 nm could be detected by the proposed dual-band UV-PDs. When a reverse bias voltage of −5 V was applied on the dual-band UV-PDs, the photoresponsivity at 310 and 360 nm was 196.0 and 0.70 A/W, respectively. The noise equivalent power at 310 and 360 nm was 9.81 × 10−15 W and 2.78 × 10−12 W, respectively. Furthermore, the specific detectivity at 310 and 360 nm was 9.67 × 1013 and 3.41 × 1011 cmHz0.5W−1, respectively.