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Can graphene make better HgCdTe infrared detectors?

Xu W, Gong Y, Liu L, Qin H, Shi Y - Nanoscale Res Lett (2011)

Bottom Line: We develop a simple and low-cost technique based on chemical vapor deposition from which large-size graphene films with 5-10 graphene layers can be produced reliably and the graphene films can be transferred easily onto HgCdTe (MCT) thin wafers at room temperature.It is found that the averaged light transmittance of the graphene film on MCT thin wafer is about 80% in the mid-infrared bandwidth at room temperature and 77 K.Moreover, we find that the electrical conductance of the graphene film on the MCT substrate is about 25 times larger than that of the MCT substrate at room temperature and 77 K.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, Yunnan University, Kunming 650091, China. wenxu_issp@yahoo.cn.

ABSTRACT
We develop a simple and low-cost technique based on chemical vapor deposition from which large-size graphene films with 5-10 graphene layers can be produced reliably and the graphene films can be transferred easily onto HgCdTe (MCT) thin wafers at room temperature. The proposed technique does not cause any thermal and mechanical damages to the MCT wafers. It is found that the averaged light transmittance of the graphene film on MCT thin wafer is about 80% in the mid-infrared bandwidth at room temperature and 77 K. Moreover, we find that the electrical conductance of the graphene film on the MCT substrate is about 25 times larger than that of the MCT substrate at room temperature and 77 K. These experimental findings suggest that, from a physics point of view, graphene can be utilized as transparent electrodes as a replacement for metal electrodes while producing better and cheaper MCT infrared detectors.

No MeSH data available.


Related in: MedlinePlus

I-V relations, obtained from four-point measurements, for graphene on MCT substrate and for sole MCT wafer at room temperature. Here, RMCT and RG are the resistances, respectively, for the MCT substrate and for the graphene film, and G is the resistivity for graphene layer on MCT thin wafer.
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Figure 3: I-V relations, obtained from four-point measurements, for graphene on MCT substrate and for sole MCT wafer at room temperature. Here, RMCT and RG are the resistances, respectively, for the MCT substrate and for the graphene film, and G is the resistivity for graphene layer on MCT thin wafer.

Mentions: The I-V relations obtained from the four-point measurements for graphene film on MCT substrate and for MCT wafer alone are shown in Figure 3 at room temperature. We find that the resistance of the graphene film on MCT (RG ~ 623 Ω/sq) is nearly 25 times less than that of the MCT wafer (RMCT ~ 15265 Ω/sq). The resistivity of the graphene film with 5-10 graphene layers on MCT wafer is about 0.17 Ω·m at room temperature. There is a small difference between RMCT and RG values at T = 77 K and at room-temperature. We have also measured the photo-resistance of the graphene film on the thin MCT substrate when MIR radiation fields, polarized linearly, are applied. It is found that there is a slight decrease in both RG and RMCT in the presence of MIR radiation. Those experimental findings indicate that the conductance and photo-conductance of a graphene film with 5-10 graphene layers are much lager than those of the MCT thin wafer in the MIR bandwidth at room temperature and 77 K (the operating temperature of the MCT infrared detectors).


Can graphene make better HgCdTe infrared detectors?

Xu W, Gong Y, Liu L, Qin H, Shi Y - Nanoscale Res Lett (2011)

I-V relations, obtained from four-point measurements, for graphene on MCT substrate and for sole MCT wafer at room temperature. Here, RMCT and RG are the resistances, respectively, for the MCT substrate and for the graphene film, and G is the resistivity for graphene layer on MCT thin wafer.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211312&req=5

Figure 3: I-V relations, obtained from four-point measurements, for graphene on MCT substrate and for sole MCT wafer at room temperature. Here, RMCT and RG are the resistances, respectively, for the MCT substrate and for the graphene film, and G is the resistivity for graphene layer on MCT thin wafer.
Mentions: The I-V relations obtained from the four-point measurements for graphene film on MCT substrate and for MCT wafer alone are shown in Figure 3 at room temperature. We find that the resistance of the graphene film on MCT (RG ~ 623 Ω/sq) is nearly 25 times less than that of the MCT wafer (RMCT ~ 15265 Ω/sq). The resistivity of the graphene film with 5-10 graphene layers on MCT wafer is about 0.17 Ω·m at room temperature. There is a small difference between RMCT and RG values at T = 77 K and at room-temperature. We have also measured the photo-resistance of the graphene film on the thin MCT substrate when MIR radiation fields, polarized linearly, are applied. It is found that there is a slight decrease in both RG and RMCT in the presence of MIR radiation. Those experimental findings indicate that the conductance and photo-conductance of a graphene film with 5-10 graphene layers are much lager than those of the MCT thin wafer in the MIR bandwidth at room temperature and 77 K (the operating temperature of the MCT infrared detectors).

Bottom Line: We develop a simple and low-cost technique based on chemical vapor deposition from which large-size graphene films with 5-10 graphene layers can be produced reliably and the graphene films can be transferred easily onto HgCdTe (MCT) thin wafers at room temperature.It is found that the averaged light transmittance of the graphene film on MCT thin wafer is about 80% in the mid-infrared bandwidth at room temperature and 77 K.Moreover, we find that the electrical conductance of the graphene film on the MCT substrate is about 25 times larger than that of the MCT substrate at room temperature and 77 K.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, Yunnan University, Kunming 650091, China. wenxu_issp@yahoo.cn.

ABSTRACT
We develop a simple and low-cost technique based on chemical vapor deposition from which large-size graphene films with 5-10 graphene layers can be produced reliably and the graphene films can be transferred easily onto HgCdTe (MCT) thin wafers at room temperature. The proposed technique does not cause any thermal and mechanical damages to the MCT wafers. It is found that the averaged light transmittance of the graphene film on MCT thin wafer is about 80% in the mid-infrared bandwidth at room temperature and 77 K. Moreover, we find that the electrical conductance of the graphene film on the MCT substrate is about 25 times larger than that of the MCT substrate at room temperature and 77 K. These experimental findings suggest that, from a physics point of view, graphene can be utilized as transparent electrodes as a replacement for metal electrodes while producing better and cheaper MCT infrared detectors.

No MeSH data available.


Related in: MedlinePlus