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Highly sensitive ultraviolet photodetectors fabricated from ZnO quantum dots/carbon nanodots hybrid films.

Guo DY, Shan CX, Qu SN, Shen DZ - Sci Rep (2014)

Bottom Line: The photodetectors can be used to detect very weak ultraviolet signals (as low as 12 nW/cm(2)).The detectivity and noise equivalent power of the photodetector can reach 3.1 × 10(17) cmHz(1/2)/W and 7.8 × 10(-20) W, respectively, both of which are the best values ever reported for ZnO-based photodetectors.The mechanism for the high sensitivity of the photodetectors has been attributed to the enhanced carrier-separation at the ZnO/C interface.

View Article: PubMed Central - PubMed

Affiliation: 1] State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China [2] University of Chinese Academy of Sciences, Beijing 10049, China.

ABSTRACT
Ultraviolet photodetectors have been fabricated from ZnO quantum dots/carbon nanodots hybrid films, and the introduction of carbon nanodots improves the performance of the photodetectors greatly. The photodetectors can be used to detect very weak ultraviolet signals (as low as 12 nW/cm(2)). The detectivity and noise equivalent power of the photodetector can reach 3.1 × 10(17) cmHz(1/2)/W and 7.8 × 10(-20) W, respectively, both of which are the best values ever reported for ZnO-based photodetectors. The mechanism for the high sensitivity of the photodetectors has been attributed to the enhanced carrier-separation at the ZnO/C interface.

No MeSH data available.


Related in: MedlinePlus

(a) Response spectra of the photodetectors fabricated from the ZnO QD/carbon nanodots hybrid film with different ratios under a bias of 50 mV; (b) Dependence of the responsivity of the photodetectors fabricated from the ZnO/C hybrid films and bare ZnO QDs on the bias voltage.
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f5: (a) Response spectra of the photodetectors fabricated from the ZnO QD/carbon nanodots hybrid film with different ratios under a bias of 50 mV; (b) Dependence of the responsivity of the photodetectors fabricated from the ZnO/C hybrid films and bare ZnO QDs on the bias voltage.

Mentions: We note that the photodetectors show obvious response even when the illumination source is as weak as 12 nW/cm2. The response spectrum of the photodetectors fabricated from the hybrid films with different ratios at a bias voltage of 50 mV is shown in Fig. 5, and that of the photodetector fabricated from bare ZnO QDs is also plotted for comparison. One can see that the response spectra of the photodetector fabricated from the hybrid films are very similar in shape with that of the device fabricated from bare ZnO QDs, and all the spectra show a maximum response at around 370 nm. A noteworthy phenomenon in the spectra lies in the fact that the responsivity of the photodetectors fabricated from the hybrid films is much higher than that from bare ZnO QDs. Note that the response curves of the devices recorded one year later are almost identical to the ones recorded before as the devices are kept in a tinfoil sealed desiccator, indicating the good reliability of the photodetectors. The device fabricated from ZnO/C ratio of 2: 1 shows the largest responsivity, thus this device has been selected as a representative in the following investigations. The inset of Fig. 5 shows the dependence of the peak responsivity of the photodetectors fabricated from ZnO/C hybrid films and bare ZnO QDs on the bias applied. The responsivity increases monotonically with the bias in both cases, and the responsivity of the photodetector fabricated from ZnO QD/carbon nanodots hybrid films can reach 1.7 × 106 A/W, while that of the photodetector fabricated from bare ZnO QDs is 9.7 × 104 A/W reaches 14 V. That is, the responsivity of the device fabricated from the hybrid films is over two orders higher than that of the device fabricated from bare ZnO QDs.


Highly sensitive ultraviolet photodetectors fabricated from ZnO quantum dots/carbon nanodots hybrid films.

Guo DY, Shan CX, Qu SN, Shen DZ - Sci Rep (2014)

(a) Response spectra of the photodetectors fabricated from the ZnO QD/carbon nanodots hybrid film with different ratios under a bias of 50 mV; (b) Dependence of the responsivity of the photodetectors fabricated from the ZnO/C hybrid films and bare ZnO QDs on the bias voltage.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4264006&req=5

f5: (a) Response spectra of the photodetectors fabricated from the ZnO QD/carbon nanodots hybrid film with different ratios under a bias of 50 mV; (b) Dependence of the responsivity of the photodetectors fabricated from the ZnO/C hybrid films and bare ZnO QDs on the bias voltage.
Mentions: We note that the photodetectors show obvious response even when the illumination source is as weak as 12 nW/cm2. The response spectrum of the photodetectors fabricated from the hybrid films with different ratios at a bias voltage of 50 mV is shown in Fig. 5, and that of the photodetector fabricated from bare ZnO QDs is also plotted for comparison. One can see that the response spectra of the photodetector fabricated from the hybrid films are very similar in shape with that of the device fabricated from bare ZnO QDs, and all the spectra show a maximum response at around 370 nm. A noteworthy phenomenon in the spectra lies in the fact that the responsivity of the photodetectors fabricated from the hybrid films is much higher than that from bare ZnO QDs. Note that the response curves of the devices recorded one year later are almost identical to the ones recorded before as the devices are kept in a tinfoil sealed desiccator, indicating the good reliability of the photodetectors. The device fabricated from ZnO/C ratio of 2: 1 shows the largest responsivity, thus this device has been selected as a representative in the following investigations. The inset of Fig. 5 shows the dependence of the peak responsivity of the photodetectors fabricated from ZnO/C hybrid films and bare ZnO QDs on the bias applied. The responsivity increases monotonically with the bias in both cases, and the responsivity of the photodetector fabricated from ZnO QD/carbon nanodots hybrid films can reach 1.7 × 106 A/W, while that of the photodetector fabricated from bare ZnO QDs is 9.7 × 104 A/W reaches 14 V. That is, the responsivity of the device fabricated from the hybrid films is over two orders higher than that of the device fabricated from bare ZnO QDs.

Bottom Line: The photodetectors can be used to detect very weak ultraviolet signals (as low as 12 nW/cm(2)).The detectivity and noise equivalent power of the photodetector can reach 3.1 × 10(17) cmHz(1/2)/W and 7.8 × 10(-20) W, respectively, both of which are the best values ever reported for ZnO-based photodetectors.The mechanism for the high sensitivity of the photodetectors has been attributed to the enhanced carrier-separation at the ZnO/C interface.

View Article: PubMed Central - PubMed

Affiliation: 1] State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China [2] University of Chinese Academy of Sciences, Beijing 10049, China.

ABSTRACT
Ultraviolet photodetectors have been fabricated from ZnO quantum dots/carbon nanodots hybrid films, and the introduction of carbon nanodots improves the performance of the photodetectors greatly. The photodetectors can be used to detect very weak ultraviolet signals (as low as 12 nW/cm(2)). The detectivity and noise equivalent power of the photodetector can reach 3.1 × 10(17) cmHz(1/2)/W and 7.8 × 10(-20) W, respectively, both of which are the best values ever reported for ZnO-based photodetectors. The mechanism for the high sensitivity of the photodetectors has been attributed to the enhanced carrier-separation at the ZnO/C interface.

No MeSH data available.


Related in: MedlinePlus