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Xu et al. Nanoscale Research Letters 2011, 6:250

Xu et al. Nanoscale Research Letters 2011, 6:250 http://www.nanoscalereslett.com/content/6/1/250 NANO EXPRESS Open Access Can graphene make better HgCdTe infrared detectors? Wen Xu1,2*, Youpin Gong3, Liwei Liu3*, Hua Qin3 and Yanli Shi4 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. | Xu et al. Nanoscale Research Letters 2011 6 250 http www.nanoscalereslett.eom content 6 1 250 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Can graphene make better HgCdTe infrared detectors Wen Xu1 2 Youpin Gong 3 Liwei Liu3 Hua Qin3 and Yanli Shi4 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. Introduction As an ideal two-dimensional 2D electronic system 2DES graphene single or a few layers of carbon atoms arranged in a hexagonal lattice 1 has excellent electronic electrical transport and optical properties and interesting physical features 2 . Electronically the carrier density in graphene 3 can be as high as 1013 cm-2. It is much larger than that in conventional III-V and SiGe-based 2DESs. More importantly the carrier density in graphene can be turned easily and efficiently through applying the gate voltages 4 . From an electrical transport point of view graphene has very high carrier mobility 5 which can reach up to 20 m2 Vs at room temperature. This value of carrier mobility is about 100 times larger than that in conventional Si-based materials. Furthermore and optically