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Role of different scattering mechanisms on the temperature dependence of transport in graphene.

Sarkar S, Amin KR, Modak R, Singh A, Mukerjee S, Bid A - Sci Rep (2015)

Bottom Line: We find that for high mobility devices the transport properties are mainly governed by completely screened short range impurity scattering.On the other hand, for the low mobility devices transport properties are determined by both types of scattering potentials - long range due to ionized impurities and short range due to completely screened charged impurities.The results could be explained in the framework of Boltzmann transport equations involving the two independent scattering mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Indian Institute of Science, Bangalore 560012, India.

ABSTRACT
Detailed experimental and theoretical studies of the temperature dependence of the effect of different scattering mechanisms on electrical transport properties of graphene devices are presented. We find that for high mobility devices the transport properties are mainly governed by completely screened short range impurity scattering. On the other hand, for the low mobility devices transport properties are determined by both types of scattering potentials - long range due to ionized impurities and short range due to completely screened charged impurities. The results could be explained in the framework of Boltzmann transport equations involving the two independent scattering mechanisms.

No MeSH data available.


Related in: MedlinePlus

Variation of dR/dT with the chemical potential εF at different temperatures.The scatter points are the measured experimental data while the solid lines are best fits from our theoretical calculation. The data are presented for two different devices - (a) relatively low mobility device g7m5 and (b) relatively high mobility device g28m6.
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f6: Variation of dR/dT with the chemical potential εF at different temperatures.The scatter points are the measured experimental data while the solid lines are best fits from our theoretical calculation. The data are presented for two different devices - (a) relatively low mobility device g7m5 and (b) relatively high mobility device g28m6.

Mentions: In Fig. 6 we have plotted the dR/dT as a function of the chemical potential εF for two different devices - (a) g7m5 which is a relatively low mobility device and (b) g28m6 which is a high mobility device. It can be seen that the fits to the experimental data using our semi-classical theory near the Dirac point works much better in the case of the high mobility device than for the device with low mobility. This can be understood as follows: the semi-classical Boltzmann transport calculations presented here are based on the one-band approximation1112. It is generally expected that such semi-classical models should break down in the vicinity of zero doping as εFτ becomes comparable to ħ. Having said that, it was recently shown that for short-range scatterers (which, as shown below, are the primary sources of scattering for high mobility SLG) the carrier momentum relaxation time diverges near the zero doping limit36. Thus the value of εFτ (and consequently the validity of semi-classical treatment) depends not only on the carrier concentration but also critically on the scattering mechanism30.


Role of different scattering mechanisms on the temperature dependence of transport in graphene.

Sarkar S, Amin KR, Modak R, Singh A, Mukerjee S, Bid A - Sci Rep (2015)

Variation of dR/dT with the chemical potential εF at different temperatures.The scatter points are the measured experimental data while the solid lines are best fits from our theoretical calculation. The data are presented for two different devices - (a) relatively low mobility device g7m5 and (b) relatively high mobility device g28m6.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4660441&req=5

f6: Variation of dR/dT with the chemical potential εF at different temperatures.The scatter points are the measured experimental data while the solid lines are best fits from our theoretical calculation. The data are presented for two different devices - (a) relatively low mobility device g7m5 and (b) relatively high mobility device g28m6.
Mentions: In Fig. 6 we have plotted the dR/dT as a function of the chemical potential εF for two different devices - (a) g7m5 which is a relatively low mobility device and (b) g28m6 which is a high mobility device. It can be seen that the fits to the experimental data using our semi-classical theory near the Dirac point works much better in the case of the high mobility device than for the device with low mobility. This can be understood as follows: the semi-classical Boltzmann transport calculations presented here are based on the one-band approximation1112. It is generally expected that such semi-classical models should break down in the vicinity of zero doping as εFτ becomes comparable to ħ. Having said that, it was recently shown that for short-range scatterers (which, as shown below, are the primary sources of scattering for high mobility SLG) the carrier momentum relaxation time diverges near the zero doping limit36. Thus the value of εFτ (and consequently the validity of semi-classical treatment) depends not only on the carrier concentration but also critically on the scattering mechanism30.

Bottom Line: We find that for high mobility devices the transport properties are mainly governed by completely screened short range impurity scattering.On the other hand, for the low mobility devices transport properties are determined by both types of scattering potentials - long range due to ionized impurities and short range due to completely screened charged impurities.The results could be explained in the framework of Boltzmann transport equations involving the two independent scattering mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Indian Institute of Science, Bangalore 560012, India.

ABSTRACT
Detailed experimental and theoretical studies of the temperature dependence of the effect of different scattering mechanisms on electrical transport properties of graphene devices are presented. We find that for high mobility devices the transport properties are mainly governed by completely screened short range impurity scattering. On the other hand, for the low mobility devices transport properties are determined by both types of scattering potentials - long range due to ionized impurities and short range due to completely screened charged impurities. The results could be explained in the framework of Boltzmann transport equations involving the two independent scattering mechanisms.

No MeSH data available.


Related in: MedlinePlus