46
General Questions and Answers / Re: current-gate voltage curves
« on: December 21, 2014, 10:32 »
I have found the error in the script. You needn't answer this question.
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47
General Questions and Answers / current-gate voltage curves
« on: December 21, 2014, 08:40 »
Dear sir, I have used the script to draw the current-gate voltage curve from the transmission at different gate voltage and bias voltage = 0 V. But there is no curve shown in the figure after a long period of calculation. What is wrong with the script?
Script:
#make list of relevant gate voltages
gate_voltage_list=numpy.linspace(-1.0,1.0,11)*Volt
#make list to hold the current calculations
current_list=numpy.zeros(len(gate_voltage_list))
current_list=current_list.reshape(len(gate_voltage_list))
#specify the filename for the netcdf data file
filename="F:/MoS2/MoS2/VD=0.5V/gatescan-MoS2-0V-2.nc"
#loop through the gate voltages
for n in range(len(gate_voltage_list)):
transmission_spectrum=nlread('F:/MoS2/MoS2/VD=0.5V/gatescan-MoS2-0V-2.nc',
object_id="trans"+str(gate_voltage_list[n]))[0]
#plot the current as function of gatevoltage
import pylab
pylab.figure()
pylab.xlabel("Gate Voltage (V)")
pylab.ylabel("Current (A)")
pylab.show()
Script:
#make list of relevant gate voltages
gate_voltage_list=numpy.linspace(-1.0,1.0,11)*Volt
#make list to hold the current calculations
current_list=numpy.zeros(len(gate_voltage_list))
current_list=current_list.reshape(len(gate_voltage_list))
#specify the filename for the netcdf data file
filename="F:/MoS2/MoS2/VD=0.5V/gatescan-MoS2-0V-2.nc"
#loop through the gate voltages
for n in range(len(gate_voltage_list)):
transmission_spectrum=nlread('F:/MoS2/MoS2/VD=0.5V/gatescan-MoS2-0V-2.nc',
object_id="trans"+str(gate_voltage_list[n]))[0]
#plot the current as function of gatevoltage
import pylab
pylab.figure()
pylab.xlabel("Gate Voltage (V)")
pylab.ylabel("Current (A)")
pylab.show()
48
General Questions and Answers / Re: negative transmission coefficiencies of monolayer MoS2 FET
« on: December 18, 2014, 04:07 »
11.8.2
It seems that I have found the reason for the negative transmission. The transmission is calculated without SCF iteration. Thanks very much for your helpful suggestions
It seems that I have found the reason for the negative transmission. The transmission is calculated without SCF iteration. Thanks very much for your helpful suggestions
49
General Questions and Answers / Re: negative transmission coefficiencies of monolayer MoS2 FET
« on: December 17, 2014, 10:10 »Probably you used Krylov self-energy method? Anyway, negative values of 1e-11 has no influence on the current anyway, but switch to Recursion to avoid negative values in general.Sir,
I am sure that I have used Recursion to calculate the self-energy and there is no negative transmission coefficiencies at Vg = 0. But when gate voltage is applied, the negative transmission coefficiencies occur, some are larger than 1e-5. I am afraid that such values can not be neglected.
50
General Questions and Answers / negative transmission coefficiencies of monolayer MoS2 FET
« on: December 17, 2014, 06:44 »
Dear sir,
I calculated the gatescan curves of monolayer MoS2 FET. At the Vg = -1.0 V and 0.5 V and VD = 0 V, many values of transmission coefficiencies are negativeļ¼ especially near E = 0 eV. The monolayer MoS2 is optimized until the max force is less 0.1 eV/A. Resursion is used to tackle with the self-energy calculation and transmission.
Would you please tell me what is the problem with the negative transmission coefficiencies? The attached files are the detailed transmission coefficiencies of monolayer MoS2 at Vg = 0.5 V and VD = 0 V and the optimized MoS2 device.
Should the device be re-optimized after the dielectric layer and metallic layer is added on the MoS2?
I calculated the gatescan curves of monolayer MoS2 FET. At the Vg = -1.0 V and 0.5 V and VD = 0 V, many values of transmission coefficiencies are negativeļ¼ especially near E = 0 eV. The monolayer MoS2 is optimized until the max force is less 0.1 eV/A. Resursion is used to tackle with the self-energy calculation and transmission.
Would you please tell me what is the problem with the negative transmission coefficiencies? The attached files are the detailed transmission coefficiencies of monolayer MoS2 at Vg = 0.5 V and VD = 0 V and the optimized MoS2 device.
Should the device be re-optimized after the dielectric layer and metallic layer is added on the MoS2?