Dear ATK developers:
Recently, I have dug on the function of photocurrent implemented in QuantumATK 2018.06. But, I have a few confusing questions about this function.
1) The manual gives the formula about how to calculate photocurrent,
I_{\alpha, \sigma} = \frac{e}{\hbar}\int \frac{dE}{2\pi}\sum_{k} T_\alpha(E, k, \sigma).
What are the lower and upper limits of the integral?
2) The obtained photocurrent from the above formula is just a photo induced current, which is a correction to the bias induced correction, Right? That is, the photocurrent does not contains the bias induced current.
3) How does the photocurrent flow, that is the flow direction, through a molecular junction, for zero bias and a finite bias?
4) On can only include the bias effect on photocurrent by using a *hdf5 file for a two probe junction converged under a bias?
Can you please kindly provide some more elementary tutorials or instructions or readings on photocurrent about, for example, the mechanism, etc.
With best regards,
/Guang-Ping Zhang
