Discrete Energy Level (Domains)
The Discrete Energy Level subnode is available from the context menu (right-click the parent node) or from the Physics toolbar, Attributes menu when Explicit trap distribution is selected as the Domain trapping model for the Trap-Assisted Recombination node. Use this feature to specify a single discrete energy level for the traps.
Trap type
This section is available when the Specify trap species check box is selected for the parent node. Different trap types have a different charge when they are occupied or unoccupied. Select a Trap type:
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Donor traps. Neutral when unionized (occupied by electron) and positively charged when ionized (unoccupied by electron).
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Acceptor traps. Neutral when unionized (occupied by hole) and negatively charged when ionized (unoccupied by hole, i.e. filled by electron).
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Neutral electron traps. Negatively charged when occupied (electron trapped) and neutral when unoccupied (no electron trapped).
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Neutral hole traps. Positively charged when occupied (hole trapped) and neutral when unoccupied (no hole trapped).
Traps
When there is no Trap type defined, enter a Trap number density Nt (SI unit: 1/m3). The default is 1 × 1012 1/cm3.
When the Trap type is defined, enter one of the following:
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Donor trap density Nt,d (SI unit: 1/m3). The default is 1 × 1012 1/cm3.
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Acceptor trap density Nt,a (SI unit: 1/m3). The default is 1 × 1012 1/cm3.
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Neutral electron trap density Nt,ne (SI unit: 1/m3). The default is 1 × 1012 1/cm3.
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Neutral hole trap density Nt,nh (SI unit: 1/m3). The default is 1 × 1012 1/cm3.
For any option, select an Impurity energy level — Midgap (the default), From valence band edge, From conduction band edge, or Relative. Then enter the applicable information:
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Impurity energy level (available when From valence band edge or From conduction band edge is selected) Et,0 (SI unit: V). The default is 0 V.
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Impurity energy level (between 0 and 1, 0 being the valence band) (available when Relative is selected) Et,0 (dimensionless). The default is 0.5.
Enter the Ground-state degeneracy factor gd (dimensionless). The default is 1.
Enter the Trap occupancy initial value ft,init (dimensionless). The default is 0.5.
Carrier Capture
Choose how to define the Probability of electron capture (Cn) — From cross section (the default) or User defined.
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For From cross section, enter an Averaged cross section for electron capture <σn> (SI unit: m2; the default is 1 × 1018 1/cm2) and Electron thermal velocity Vthn (SI unit: m/s; the default is 1.562 × 107 m/s).
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For User defined, enter Cn (SI unit: m3/s). The default is 2.042 × 10-11 cm3/s.
Define the Probability of hole capture (Cp) — From cross section (the default) or User defined.
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For From cross section, enter an Averaged cross section for hole capture <σp> (SI unit: m2; the default is 1 × 1018 1/cm2) and Hole thermal velocity Vthp (SI unit: m/s; the default is 1.562 × 107 m/s).
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For User defined enter Cp (SI unit: m3/s). The default is 1.562 × 10-11 cm3/s.