Adding direct btbt by Hurkx

Author: marc-flex

docs/api/charge/mediums.rst

@@ -34,6 +34,7 @@ Generation Recombination
    tidy3d.ShockleyReedHallRecombination
    tidy3d.FossumCarrierLifetime
    tidy3d.DistributedGeneration
+   tidy3d.HurkxDirectBandToBandTunneling
 
 
 Doping

tidy3d/__init__.py

@@ -83,6 +83,7 @@
     HeatFluxBC,
     HeatFromElectricSource,
     HeatSource,
+    HurkxDirectBandToBandTunneling,
     InsulatingBC,
     IsotropicEffectiveDOS,
     MultiValleyEffectiveDOS,
@@ -603,6 +604,7 @@ def set_logging_level(level: str) -> None:
     "HeatSource",
     "HeuristicPECStaircasing",
     "HuraySurfaceRoughness",
+    "HurkxDirectBandToBandTunneling",
     "IndexPerturbation",
     "IndexedDataArray",
     "IndexedFieldVoltageDataArray",

tidy3d/components/tcad/generation_recombination.py

@@ -223,3 +223,52 @@ def check_spatialdataarray_dimensions(cls, values):
             raise ValueError("SpatialDataArray must be at least 2D.")
 
         return values
+
+
+class HurkxDirectBandToBandTunneling(Tidy3dBaseModel):
+    """
+    This class defines a direct band-to-band tunneling recombination model based on the Hurkx model
+    as described in [1]_.
+
+    Notes
+    -----
+
+        The direct band-to-band tunneling recombination rate ``R_{BTBT}`` is primarily defined by the
+        material's bandgap energy :math:`E_g` and the electric field :math:`F`.
+
+        .. math::
+
+            R^{BTBT} = A \\cdot \frac{n \\cdot p - n_i^2}{(n + n_i) \\cdot (p + n_i)} \\cdot \\left( \frac{|\\mathbf{E}|}{E_0} \right)^{\\sigma} \\cdot \\exp \\left( -\frac{B}{|\\mathbf{E}|} \\cdot \\left( \frac{E_g}{E_{g,300}} \right)^{3/2} \right )
+
+        where :math:`A`, :math:`B`, :math:`E_0`, and :math:`\\sigma` are material-dependent parameters.
+
+    References
+    ----------
+        .. [1] Palankovski, Vassil, and Rüdiger Quay. Analysis and simulation of heterostructure devices. Springer Science & Business Media, 2004.
+    """
+
+    A: float = pd.Field(
+        4e14,
+        title="Parameter A",
+        description="Parameter A in the direct BTBT Hurkx model.",
+        units="1/(cm^3 s)",
+    )
+    B: float = pd.Field(
+        1.9e6,
+        title="Parameter B",
+        description="Parameter B in the direct BTBT Hurkx model.",
+        units="V/cm",
+    )
+    E_0: float = pd.Field(
+        1,
+        title="Reference electric field E_0",
+        description="Reference electric field E_0 in the direct BTBT Hurkx model.",
+        units="V/cm",
+    )
+    sigma: float = pd.Field(
+        ...,
+        title="Exponent parameter",
+        description="Exponent sigma in the direct BTBT Hurkx model. For direct "
+        "semiconductors sigma is typically 2.0, while for indirect "
+        "semiconductors sigma is typically 2.5.",
+    )

tidy3d/components/tcad/types.py

@@ -24,6 +24,7 @@
 from tidy3d.components.tcad.generation_recombination import (
     AugerRecombination,
     DistributedGeneration,
+    HurkxDirectBandToBandTunneling,
     RadiativeRecombination,
     ShockleyReedHallRecombination,
 )
@@ -46,7 +47,11 @@
 EnergyBandGapModelType = Union[ConstantEnergyBandGap, VarshniEnergyBandGap]
 MobilityModelType = Union[CaugheyThomasMobility, ConstantMobilityModel]
 RecombinationModelType = Union[
-    AugerRecombination, DistributedGeneration, RadiativeRecombination, ShockleyReedHallRecombination
+    AugerRecombination,
+    DistributedGeneration,
+    RadiativeRecombination,
+    ShockleyReedHallRecombination,
+    HurkxDirectBandToBandTunneling,
 ]
 BandGapNarrowingModelType = Union[SlotboomBandGapNarrowing]