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Multicolor Photodetector of a Single Er(3+)-Doped CdS Nanoribbon.

Dedong H, Ying-Kai L, Yu DP - Nanoscale Res Lett (2015)

Bottom Line: It is found that Er-CdS NR has the ability of detecting multicolor light including blue, red, and near-infrared light with higher responsivity (R λ ) and external quantum efficiency (η).These results indicated that ionized impurities and the intrinsic excitation are responsible for the conductance change of Er-CdS NR in the dark.The superior performance of the Er-CdS NR device offers an avenue to develop highly sensitive multicolor photodetector applications.

View Article: PubMed Central - PubMed

Affiliation: Institute of Physics and Electronic Information, Yunnan Normal University, No. 768 Juxian Street, Chenggong New District, Kunming, 650500, People's Republic of China, ddhou@126.com.

ABSTRACT
Er(3+)-doped CdS nanoribbons (Er-CdS NRs) are synthesized by thermal evaporation and then characterized by field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL), and absorption spectra. The Er-CdS NR photodetector is studied systematically, including spectral response, light intensity response, and photoconductance (G) versus temperature (T). It is found that Er-CdS NR has the ability of detecting multicolor light including blue, red, and near-infrared light with higher responsivity (R λ ) and external quantum efficiency (η). The conductance of Er-CdS NR under dark conditions decreases with increasing temperature in the range of 87-237 K, while its conductance increases with increasing temperature in the range of 237-297 K when T is larger than 237 K. These results indicated that ionized impurities and the intrinsic excitation are responsible for the conductance change of Er-CdS NR in the dark. The superior performance of the Er-CdS NR device offers an avenue to develop highly sensitive multicolor photodetector applications.

No MeSH data available.


Related in: MedlinePlus

The relations between PC, DC, and temperature. a The dark conductance (DC) versus temperature curve of the Er-CdS NR detector. b Photoconductance (PC) dependence on the temperature of the Er-CdS NR detector. c The ratio of PC to DC versus temperature curve of the Er-CdS NR detector
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Fig7: The relations between PC, DC, and temperature. a The dark conductance (DC) versus temperature curve of the Er-CdS NR detector. b Photoconductance (PC) dependence on the temperature of the Er-CdS NR detector. c The ratio of PC to DC versus temperature curve of the Er-CdS NR detector

Mentions: To further investigate the surface-related processes and the transport processes of Er-CdS NRs, the dark conductance (hereafter denoted as DC), PC, and PC ratio were tested as a function of working temperature under illumination with an incandescent lamp and dark conditions in vacuum. Figure 7a exhibits the dependence of the dark conductance (G) on the temperature (T) at fixed intensity and voltage in vacuum (the pressure is in the range of 2.4~3.4 × 10−1 Torr). It is found that DC of the Er-CdS NR decreases with increasing operating temperature in the range of 87–237 K, indicating that the impurities are completely ionized and the intrinsic excitation is not primary [29], whereas the mobility decreases with increasing temperature; therefore, its DC reduces at the temperatures range of 87–237 K. However, DC of the Er-CdS NR increases with increasing temperature when T is larger than 237 K within the temperature range of 237–297 K, revealing that the intrinsic excitation quickly increases, and the yield of intrinsic carriers has more influence on DC of the Er-CdS NR than on the decrease of mobility. The intrinsic carriers have larger contributions to its DC. Therefore, DC decreases with increasing temperature, exhibiting the properties of intrinsic semiconductors. This result also reveals that the intrinsic carriers govern the dark conductance change. PC dependence of the Er-CdS NR on the temperature is shown in Fig. 7b under irradiation of incandescent light. It is found that PC of the CdS nanoribbon decreases with increasing temperature in the range of 87–297 K, which demonstrated that the intrinsic electron-hole (e-h) pairs are produced as soon as Er-CdS NR is illuminated by incandescent light and then the carriers are supplied drastically. As a result, its PC increases.Fig. 7


Multicolor Photodetector of a Single Er(3+)-Doped CdS Nanoribbon.

Dedong H, Ying-Kai L, Yu DP - Nanoscale Res Lett (2015)

The relations between PC, DC, and temperature. a The dark conductance (DC) versus temperature curve of the Er-CdS NR detector. b Photoconductance (PC) dependence on the temperature of the Er-CdS NR detector. c The ratio of PC to DC versus temperature curve of the Er-CdS NR detector
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495098&req=5

Fig7: The relations between PC, DC, and temperature. a The dark conductance (DC) versus temperature curve of the Er-CdS NR detector. b Photoconductance (PC) dependence on the temperature of the Er-CdS NR detector. c The ratio of PC to DC versus temperature curve of the Er-CdS NR detector
Mentions: To further investigate the surface-related processes and the transport processes of Er-CdS NRs, the dark conductance (hereafter denoted as DC), PC, and PC ratio were tested as a function of working temperature under illumination with an incandescent lamp and dark conditions in vacuum. Figure 7a exhibits the dependence of the dark conductance (G) on the temperature (T) at fixed intensity and voltage in vacuum (the pressure is in the range of 2.4~3.4 × 10−1 Torr). It is found that DC of the Er-CdS NR decreases with increasing operating temperature in the range of 87–237 K, indicating that the impurities are completely ionized and the intrinsic excitation is not primary [29], whereas the mobility decreases with increasing temperature; therefore, its DC reduces at the temperatures range of 87–237 K. However, DC of the Er-CdS NR increases with increasing temperature when T is larger than 237 K within the temperature range of 237–297 K, revealing that the intrinsic excitation quickly increases, and the yield of intrinsic carriers has more influence on DC of the Er-CdS NR than on the decrease of mobility. The intrinsic carriers have larger contributions to its DC. Therefore, DC decreases with increasing temperature, exhibiting the properties of intrinsic semiconductors. This result also reveals that the intrinsic carriers govern the dark conductance change. PC dependence of the Er-CdS NR on the temperature is shown in Fig. 7b under irradiation of incandescent light. It is found that PC of the CdS nanoribbon decreases with increasing temperature in the range of 87–297 K, which demonstrated that the intrinsic electron-hole (e-h) pairs are produced as soon as Er-CdS NR is illuminated by incandescent light and then the carriers are supplied drastically. As a result, its PC increases.Fig. 7

Bottom Line: It is found that Er-CdS NR has the ability of detecting multicolor light including blue, red, and near-infrared light with higher responsivity (R λ ) and external quantum efficiency (η).These results indicated that ionized impurities and the intrinsic excitation are responsible for the conductance change of Er-CdS NR in the dark.The superior performance of the Er-CdS NR device offers an avenue to develop highly sensitive multicolor photodetector applications.

View Article: PubMed Central - PubMed

Affiliation: Institute of Physics and Electronic Information, Yunnan Normal University, No. 768 Juxian Street, Chenggong New District, Kunming, 650500, People's Republic of China, ddhou@126.com.

ABSTRACT
Er(3+)-doped CdS nanoribbons (Er-CdS NRs) are synthesized by thermal evaporation and then characterized by field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL), and absorption spectra. The Er-CdS NR photodetector is studied systematically, including spectral response, light intensity response, and photoconductance (G) versus temperature (T). It is found that Er-CdS NR has the ability of detecting multicolor light including blue, red, and near-infrared light with higher responsivity (R λ ) and external quantum efficiency (η). The conductance of Er-CdS NR under dark conditions decreases with increasing temperature in the range of 87-237 K, while its conductance increases with increasing temperature in the range of 237-297 K when T is larger than 237 K. These results indicated that ionized impurities and the intrinsic excitation are responsible for the conductance change of Er-CdS NR in the dark. The superior performance of the Er-CdS NR device offers an avenue to develop highly sensitive multicolor photodetector applications.

No MeSH data available.


Related in: MedlinePlus