Updated comments and small fixes

Author: damiano-flex

tests/test_components/test_heat_charge.py

@@ -8,6 +8,7 @@
 from matplotlib import pyplot as plt
 
 import tidy3d as td
+from tidy3d.components.tcad.simulation.heat_charge import TCADAnalysisTypes
 from tidy3d.components.tcad.types import (
     AugerRecombination,
     CaugheyThomasMobility,
@@ -2513,3 +2514,88 @@ def test_generation_recombination():
         beta_n=1,
         beta_p=1,
     )
+
+
+def test_heat_only_simulation_with_semiconductor():
+    """Test that a heat-only simulation with semiconductors does not trigger charge simulation.
+    Charge simulations are only triggered when `analysis_spec` is provided, not just when
+    semiconductors are present in the simulation.
+    """
+
+    # Create a semiconductor medium
+    semiconductor_medium = td.MultiPhysicsMedium(
+        optical=td.Medium(permittivity=5, conductivity=0.01),
+        heat=td.SolidMedium(conductivity=3, capacity=2),
+        charge=td.SemiconductorMedium(
+            N_c=td.ConstantEffectiveDOS(N=1e10),
+            N_v=td.ConstantEffectiveDOS(N=1e10),
+            E_g=td.ConstantEnergyBandGap(eg=1),
+            mobility_n=td.ConstantMobilityModel(mu=1500),
+            mobility_p=td.ConstantMobilityModel(mu=1500),
+        ),
+        name="semiconductor",
+    )
+
+    # Create a non-semiconductor solid medium
+    solid_medium = td.MultiPhysicsMedium(
+        optical=td.Medium(permittivity=5, conductivity=0.01),
+        heat=td.SolidMedium(conductivity=1, capacity=1),
+        charge=td.ChargeConductorMedium(conductivity=1),
+        name="solid",
+    )
+
+    # Create structures with both semiconductor and other materials
+    semiconductor_structure = td.Structure(
+        geometry=td.Box(center=(-0.5, 0, 0), size=(1, 1, 1)),
+        medium=semiconductor_medium,
+        name="semiconductor_structure",
+    )
+
+    solid_structure = td.Structure(
+        geometry=td.Box(center=(0.5, 0, 0), size=(1, 1, 1)),
+        medium=solid_medium,
+        name="solid_structure",
+    )
+
+    # Create heat-only boundary conditions (no electric BCs)
+    thermal_bc = td.HeatChargeBoundarySpec(
+        condition=td.TemperatureBC(temperature=300),
+        placement=td.StructureBoundary(structure="solid_structure"),
+    )
+
+    # Create heat source
+    heat_source = td.HeatSource(structures=["solid_structure"], rate=100)
+
+    # Create heat monitor (no charge monitors)
+    temp_monitor = td.TemperatureMonitor(
+        center=(0, 0, 0), size=(2, 1, 1), name="temp_monitor", unstructured=True
+    )
+
+    # Create heat-only simulation (no analysis_spec, no electric BCs)
+    heat_sim = td.HeatChargeSimulation(
+        medium=td.MultiPhysicsMedium(
+            heat=td.FluidMedium(), charge=td.ChargeInsulatorMedium(), name="air"
+        ),
+        structures=[semiconductor_structure, solid_structure],
+        center=(0, 0, 0),
+        size=(3, 3, 3),
+        boundary_spec=[thermal_bc],
+        grid_spec=td.UniformUnstructuredGrid(dl=0.1),
+        sources=[heat_source],
+        monitors=[temp_monitor],
+        # No analysis_spec - this is key: without ChargeTypes analysis_spec,
+        # charge simulation should NOT be triggered even though semiconductors are present
+    )
+
+    # Verify that only HEAT simulation type is returned, not CHARGE
+    simulation_types = heat_sim._get_simulation_types()
+    assert TCADAnalysisTypes.HEAT in simulation_types, (
+        "Heat simulation should be triggered when heat sources/BCs are present."
+    )
+    assert TCADAnalysisTypes.CHARGE not in simulation_types, (
+        "Charge simulation should NOT be triggered when ChargeTypes analysis_spec is not provided, "
+        "even if semiconductors are present in the simulation."
+    )
+    assert TCADAnalysisTypes.CONDUCTION not in simulation_types, (
+        "Conduction simulation should NOT be triggered when no electric BCs are present."
+    )

tidy3d/components/tcad/simulation/heat_charge.py

@@ -730,14 +730,10 @@ def check_charge_simulation(cls, values):
                         )
             # check that we have at least one semiconductor medium
             structures = values["structures"]
-            sc_present = False
-            for structure in structures:
-                if isinstance(structure.medium.charge, SemiconductorMedium):
-                    sc_present = True
-                    break
+            sc_present = HeatChargeSimulation._check_if_semiconductor_present(structures=structures)
             if not sc_present:
                 raise SetupError(
-                    f"{TCADAnalysisTypes.CHARGE} simulations require the definition of, at least, one semiconductor medium."
+                    f"{TCADAnalysisTypes.CHARGE} simulations require the definition of at least one semiconductor medium."
                 )
         return values
 
@@ -910,7 +906,7 @@ def _check_simulation_types(
             if isinstance(boundary.condition, HeatBCTypes):
                 simulation_types.append(TCADAnalysisTypes.HEAT)
             if isinstance(boundary.condition, ElectricBCTypes):
-                # type CONDUCTION if we have no semiconductors
+                # Add CONDUCTION type if we have no semiconductors
                 if not semiconductor_present:
                     simulation_types.append(TCADAnalysisTypes.CONDUCTION)
 
@@ -1075,7 +1071,7 @@ def check_transient_heat(cls, values):
                         raise SetupError(
                             f"Unsteady simulations require the temperature monitor '{mnt.name}' to be unstructured."
                         )
-            # additionaly check that the SolidSpec has capacity and density defined
+            # additionally check that the SolidSpec has capacity and density defined
             capacities = []
             densities = []
             conductivities = []
@@ -1130,7 +1126,7 @@ def check_transient_heat(cls, values):
 
     @pd.root_validator(skip_on_failure=True)
     def check_non_isothermal_is_possible(cls, values):
-        """Make sure that when a non-isothermal case is defined the structrures
+        """Make sure that when a non-isothermal case is defined the structures
         have both electrical and thermal properties."""
 
         analysis_spec = values.get("analysis_spec")
@@ -1507,7 +1503,7 @@ def _construct_forward_boundaries(
     ) -> tuple[tuple[HeatChargeBoundarySpec, Shapely], ...]:
         """Construct Simulation, StructureSimulation, Structure, and MediumMedium boundaries."""
 
-        # forward foop to take care of Simulation, StructureSimulation, Structure,
+        # forward loop to take care of Simulation, StructureSimulation, Structure,
         # and MediumMediums
         boundaries = []  # bc_spec, structure name, shape, bounds
         background_shapes = []
@@ -1598,7 +1594,7 @@ def _construct_reverse_boundaries(
     ) -> tuple[tuple[HeatChargeBoundarySpec, Shapely], ...]:
         """Construct StructureStructure boundaries."""
 
-        # backward foop to take care of StructureStructure
+        # backward loop to take care of StructureStructure
         # we do it in this way because we define the boundary between
         # two overlapping structures A and B, where A comes before B, as
         # boundary(B) intersected by A
@@ -1705,7 +1701,7 @@ def _construct_heat_charge_boundaries(
 
         # construct boundaries in 2 passes:
 
-        # 1. forward foop to take care of Simulation, StructureSimulation, Structure,
+        # 1. forward loop to take care of Simulation, StructureSimulation, Structure,
         # and MediumMediums
         boundaries = HeatChargeSimulation._construct_forward_boundaries(
             shapes=shapes,