Reference geometries can be used to assign various simulation objects including doping
profiles, boundary conditions, sources and monitors to any desired volume or surface
in the simulation.
This will give users freedom to apply attributes to arbitrary geometries.
There are two major types of reference geometries.
Volumes and surfaces.
Obviously, in a two dimensional simulation, a volume will translate into a surface and
a surface will be equivalent to a line.
Now imagine there is spatial overlap between two objects in your simulation.
Reference geometries will enable users to define an attribute such as a doping profile
for a partial volume of simulation with any desired geometry like the highlighted red
area for example.
Or, for instance, a simulation object such as a monitor can be assigned to the plane
object to monitor the desired variable at the cross-section of the sphere object shared
between the two objects.
Lets explore a few examples to give you a better idea about the application of reference
We will demonstrate the application of reference geometries using an example of a core-shell
Here I have defined two materials in my simulation.
One as the core material and the other as shell.
Each one of these materials has been assigned to a geometric object forming a core-shell
Lets start with surface type ref geometries.
I will use a surface recombination boundary condition from the charge solver as an example.
The ref geometry of the objects can be assigned from the edit window of each object.
Note that I’ve switched to partitioned volume mode which will help us to find and visualize
the ref geometries we need.
the first surface type reference geometry is domain exterior this can be used to refer
to the shared surfaces between the simulation region and the exterior surfaces of the selected
You can identify your desired domain from the list of available domains in the objects
tree while you are in partitioned volume mode.
Here for example, selecting domain number 3 will result the boundary condition to be
assigned to all simulation region boundaries since they all have shared surfaces with this
BY selecting the boundary condition in partitioned volume mode you can highlight the areas it
is referring to.
the next surface type reference geometry is domain domain this will consider the surfaces
shared between two selected domains as reference.
you can identify your desired domains from the list of domains in the objects tree in
our example I can apply the boundary condition to the interface between the core and the
shell by referring to the shared surface between domain number one and number two you can now
see that the boundary condition is applied to the interface between the core and the
in addition we have the option to select a domain as a surface type reference geometry
this will create a reference geometry referring to all surfaces of the selected domain for
example here I select domain number two as a reference in order to apply my binary condition
to the interface between the core and the shell this is because this interface and domain
number two surface are essentially the same the next reference surface type is solid which
refers to the surfaces of the geometry object in the objects tree if the object has both
inner and outer surfaces checking the option outer surface only will only consider the
outer surface of the object as reference in our example I can apply the boundary condition
to the interface between the core and the shell by referring to the core as a solid
reference note that here the core object doesn't have any inner surface so checking the option
auto surface only won't make any difference another available surface type geometry is
simulation region this option can be used to refer to the boundaries of the simulation
region here for instance I can apply my boundary condition to simulation region boundaries
in the X direction by selecting X minimum and X maximum options
the next surface type reference geometry is solid simulation this will consider shared
surfaces between a solid object in the object tree and simulation region as reference this
option is not applicable to our example since there is no shared surface between the solid
object and the simulation region also available as a reference geometry is a material material
option this option can be used to refer to the interface between the areas occupied by
the two selected materials the materials can be selected from the list of materials under
materials group in the object tree here for instance I will apply my boundary condition
to the interface between core and shell objects by selecting the core and the shell material
available in the objects tree the last surface type reference geometry is
called surface this will simply consider the specific surface selected from the list of
domain surfaces available in the simulation region you can identify your desired surface
by browsing through the list of surfaces in the objects tree while being in partitioned
volume mode in our example I can apply the boundary condition to the interface between
the core and the shell which is identical to surface number two as reference.
the second major type reference geometry is volume type reference there are three different
volume type references which you won't get familiar with shortly I will use a doping
profile object as an example to demonstrate the application of volume type reference geometries
the first volume type reference geometry is called solid this will consider the volume
of a selected solid object as reference the object can be selected from the list of geometric
objects available in the objects tree for example here I can assign a doping profile
to the show object by selecting it as the solid type reference selecting the doping
profile object while in partition mode will highlight the area that the doping is assigned
to another available volume type reference geometry is domain this will refer to the
entire volume of a selected domain as reference geometry in our example I can apply a doping
profile to the shell object by selecting domain number 1 as reference geometry for the doping
profile object you can now see that the doping profile is applied to the shell the last volume
type reference geometry is called all domains selecting all domains as reference will cause
the corresponding object to be applied to all the domains seen by the solver this means
the entire simulation region is considered as reference geometry here it's obvious that
my doping profile is applied to the entire simulation region as a result of selecting
all domains we hope that this video was helpful in getting to know the concept of reference
geometries and its applications.