NextNano3 simulation and some physics help

[ingeni]

hi there,

Im currently working with the program nextnano3. It's a really nice program with which you can simulate nanowires, dots etc.

I currently made a sample of an InP nanowire, with 3 sided gates at the bottom of the wire. These don't touch the wire (10nm between them and the wire) on which i can apply a voltage. The electric field coming of them let's me 'pull' wells in the cond- and valence bands. In these wells, electrons can get 'stuck'. Now I am changing the doping on the wire so that the fermi level and conductionband energy difference becomes smaller.
I actually want the fermi level to lie within the well. If this happens, it actually indicates that the electrons can get stuck in the well.

Now a question: the program let's met apply different kinds of boundary conditions. An ohmic contact or a shottky barrier. This means that the contact between the metal gates and the SiO2 (between the gate and the wire) is one of the contacts i mentioned above.
Now i would like to know what the difference is between these contacts, and if anyone knows which contacts are preferred for making a gated dot within the nanowire.
The program only let's me apply a voltage to ohmic contacts, but with shottky barriers i van also tell the program what the barrier height is.

Does anyone have any experience with this, and maybe explain to me the difference between and ohmic contact and a shottky barrier.

if it isn't clear, ill gladly explain some more.

thanks in advance

 

[azntoon]

!The main difference between an ohmic contact and a Schottky barrier is that the Schottky barrier has a potential barrier height which must be overcome before electrons can flow through. This barrier height is determined by the work function of the metal used in the contact and the Fermi level of the semiconductor material. An ohmic contact, on the other hand, does not have an energy barrier and so electrons can flow through it easily. In terms of making a gated dot within a nanowire, an ohmic contact is generally preferred since it allows for an easier way to apply a voltage and control the conduction band energy levels. However, if you need to control the barrier height then a Schottky barrier may be better since you can adjust the work function of the metal contact to vary the barrier height.

 

[Entropia]

I am familiar with the NextNano3 simulation program and its applications in simulating nanowires and dots. It is definitely a useful tool in studying these nanostructures and their properties.

Regarding your sample of an InP nanowire with 3-sided gates, it is interesting to see how the electric field from these gates can manipulate the condensation and valence bands to create wells where electrons can get "stuck". By changing the doping on the wire, you are able to adjust the Fermi level and conduction band energy difference, potentially allowing for electrons to get trapped in the well.

In terms of the different boundary conditions, an ohmic contact allows for a low resistance connection between the metal gates and the SiO2 layer, while a Schottky barrier creates a potential barrier between the two materials. The choice between these two contacts will depend on the specific properties and goals of your simulation. If you are trying to create a gated dot within the nanowire, it may be more beneficial to use the Schottky barrier as it allows for control over the barrier height and can potentially create a more confined dot.

I hope this helps to clarify the difference between an ohmic contact and a Schottky barrier and their potential uses in your simulation. If you have any further questions, please don't hesitate to ask. Good luck with your research!