QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Arya on February 7, 2014, 01:01

Title: Getting the 'classical' LDOS for a TFET including screening length
Post by: Arya on February 7, 2014, 01:01

Hi All,

1. I calculated the LDOS for a GNR small device. To me it looks wierd (VGS = VDS = 0.4V) with -0.9 charge on left electrode and 0.9 cahrge on right electrode. Is my result correct? Have a look at attached .py and png files.

2. ATK calculates LDOS only for central region, this doesn't give us the classical picture of LDOS found in literature. Also one cannot visualize screening length from the central region picture. How can I get the LDOS as shown in 'Literature_LDOS.png' ?

The X axis in LDOS does not correspond to physical dimension of my device in transport direction. Why? I have attached the script I used to generate contour plot.

Thanks,
-Arya

Title: Re: Getting the 'classical' LDOS for a TFET including screening length
Post by: Arya on February 7, 2014, 01:04

Image of LDOS calculated by ATK..

Title: Re: Getting the 'classical' LDOS for a TFET including screening length
Post by: Anders Blom on February 24, 2014, 18:00

You can't really compare the two pictures as they are for completely different structures. The classical picture is for a classical structure, i.e. a bulk p-n junction (in Si).

0.9 is a very high charge on the electrodes, if you work out the equivalent doping concentration. You need to work backwards from a reasonable doping level and convert that to a number of electrons.

Actually you didn't attach the script for plotting, but rather for generating the data, but perhaps there is a wrong unit conversion or you are plotting grid indices instead of Z coordinates.

PS: Please don't ask the question "is my result correct". It doesn't have an answer.