# How to make a quaternary alloy

#1

This is an example of making a quaternary alloy, eg Al(x)Ga(1-x-y)In(y)Sb, to run a DEVICE simulation. This file also contains the alloy ready to use quaternary alloy.ldev (676.4 KB)

In DEVICE, an alloy material can only be created by two semiconductor type materials. Here are the steps to make a quaternary alloy:

1. user will first need to make a ternary alloy from two binary alloys, ie, GaSb + AlSb => Al(a)Ga(1-a)Sb
2. then make a ternary semiconductor from the ternary alloy
3. then combine a ternary and a binary semiconductor to make a quaternay alloy, ie, Al(a)Ga(1-a)Sb + InSb => Al(a*(1-y))Ga((1-a)*(1-y))In(y)Sb.

Note that if a = x/(1-y), the final quaternary alloy become Al(x)Ga(1-x-y)In(y)Sb. Therefore, the x and y values will need to be determined in the first place to find the value of a for step 1.

For a quaternary alloy like Ga(x)In(1-x)As(y)P(1-y), one can follow similar procedure starting with InP and Ga(a)In(1-a)As. It then become Ga(a*y)In((1-a)*y+(1-y))As(y)P(1-y), if a = x/y, then it will be Ga(x)In((1-x))As(y)P(1-y).

Step 1:
Use the AlGaSb alloy from the default database (or make it from scratch by choosing the appropriate base materials)

Step 2:
Then, this is how you could use the visualizer to find the material data for the ternary semiconductor. Here a = x/(1-y) = 0.725, where x = 0.58, y=0.2.

eg, look for the Bandgap (Eg) when a = 0.725, similarly, for the DC permittivity, effective mass, mobility, carrier lift time

To create a ternary semiconductor, you will need the information from a ternary alloy shown in the above screenshot. For the work function, one can find it assuming a linear relationship between the two base binary alloys.

Step 3:
Once you have the ternary semiconductor material done, you can now create you quaternary alloy. Leave the material data default since it will automatically interpolate it from the base materials. Once can override it by inputting the values here, if necessary.

To set the value of y(=0.2), this setting is in the Edit geometry window.

If one wants to change the x or y value, it needs to start the process again from step 1 and redo the following.

Initialization failed to converge charge update
#2

To find more details about how to create a binary, ternary, or quaternary alloy on DEVICE, check out this knowledge base page on creating a new alloy material.

#3

3 posts were split to a new topic: Setting the alloy fraction in DEVICE from script environment