QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: beauyy on December 17, 2014, 06:44
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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?
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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.
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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.
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What ATK version?
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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