QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: rupen on June 8, 2022, 11:22

Title: Defining Fermi level of gold electrodes
Post by: rupen on June 8, 2022, 11:22

Dear Sir,

I am working on metal-molecule-metal junction. I want to know where to define the fermi level of gold electrodes as by default it uses 0 eV.
Please reply asap.

regards

Title: Re: Defining Fermi level of gold electrodes
Post by: rupen on June 9, 2022, 06:33

ATK staff kindly revert back.

Title: Re: Defining Fermi level of gold electrodes
Post by: Anders Blom on June 9, 2022, 19:35

There is no need to define the Fermi level...What you can do is set the electrode biases, but once you have done that, the software will itself align all Fermi levels properly.

Title: Re: Defining Fermi level of gold electrodes
Post by: rupen on June 12, 2022, 11:07

Dear Anders Blom

As you mentioned we need not set fermi level as giving electrode biases automatically sets it but in this attachment it is written the fermi level of electrodes was kept at -ve value of gold work function which is -5.31eV. how to do this?
kindly reply at your earliest.

regards

Title: Re: Defining Fermi level of gold electrodes
Post by: Anders Blom on June 14, 2022, 09:00

In the basic case of just two electrodes (left/right , the software will take care of this automatically, and the only input you need to provide is the difference (the bias) between the electrode voltages. Shifting both of them by the same amount just redefines the overall energy zero, which doesn't change any physics.

It's a bit different if you have a gate electrode as well, because now we need to define the reference zero energy of the gate. This is discussed here:
https://docs.quantumatk.com/manual/Types/IVCharacteristics/IVCharacteristics.html#gate-potential-alignment