A broadband photodetector based on Rhodamine B-sensitized ZnO nanowires film

作者：Bai, Zheng Qi; Liu, Ze Wen^*

来源：Scientific Reports, 2017, 7(1): 11384.

DOI：10.1038/s41598-017-11154-8

• SOLAR-CELLS
• ULTRAVIOLET PHOTODETECTORS
• UV PHOTODETECTORS
• THIN-FILMS
• FABRICATION
• PHOTODIODE
• NANORODS
• DETECTOR
• GROWTH
• ARRAYS

A broadband photodetector has been developed on the basis of ZnO nanowires (NWs)/Rhodamine B (RhB) hybrid system. The device is fabricated by spraying NWs on to gold interdigital electrodes followed by modifying the NWs via an RhB solution-casting process. Measurements show that the asfabricated device demonstrates photoresponsivity ranging from 300 nm to 700 nm with a bandwidth as large as 400 nm. The role of the dye sensitizer adsorbed on the surface of NWs is modeled to alter the transportation path of photo-generated carriers. The calculations based on the measurements reveal that the device exhibits a prominent responsivity in the interested band with maximum responsivity of 5.5 A/W for ultraviolet (UV) light and 3 A/W for visible (VIS) light under 8 V bias, respectively. The sensitization not only widens the response spectrum with external quantum efficiency leaping up to 771% at VIS but also improves UV responsivity with maximum 51% enhancement. From the time-dependent photo-current measurement, it is found that the response time (rise and decay times in total) of the device largely reduced from 17.5 s to 3.3 s after sensitization. A comparison of the obtained photodetector with other ZnO-based photodetectors is summarized from the view point of responsivity and bandwidth.

• 出版日期2017-9-12
• 单位清华大学