Continuous Energy Levels (Domains)
The Continuous Energy Level subnode is available from the context menu (right-click the Trap-Assisted Recombination parent node) or from the Physics toolbar, Attributes menu when Explicit trap distribution is selected as the Domain trapping model, and Specify continuous and/or discrete levels is selected under Trapping. Use this node to define a density of trap states.
Trap Type
This section is available when the Specify trap species check box is selected for the parent node. See Discrete Energy Level (Domains).
Traps
Select a Trap density distribution — Gaussian (the default), Rectangle, Exponential, or User defined. Then enter the applicable information:
•
Width (for Gaussian distribution) σ (SI unit: V). The default is 0.333 V.
•
Width (for rectangle distribution) Ewidth(SI unit: V). The default is 0 V.
•
Size of transition zone (for rectangle distribution) ΔEtran(SI unit: V). The default is 0.05 V. This value determines the width of the smoothing employed on the step function for the rectangle distribution.
•
Damping coefficient (for exponential distribution) d (SI unit: V). The default is 0.1 V.
•
Density of trap states (for user defined) gt(E) (SI unit: s3⋅A/(m5⋅kg)). The default is 0 s3⋅A/(m5⋅kg).
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:
•
Donor trap density Nt,d (SI unit: 1/m3). The default is 1·1012 1/cm3.
•
Acceptor trap density Nt,a (SI unit: 1/m3). The default is 1·1012 1/cm3.
•
Neutral electron trap density Nt,ne (SI unit: 1/m3). The default is 1·1012 1/cm3.
•
Neutral hole trap density Nt,nh (SI unit: 1/m3). The default is 1·1012 1/cm3.
This quantity represents the total trap density, or the integrated density of states:
where g (E) is the density of trap states, and Et,min and Et,max define the range of the energy (see user inputs below), with the default being the energy levels corresponding to the conduction and valence band edges in the absence of band gap narrowing. The energy range is truncated within the default range so that there is no trap level within the conduction band or the valence band.
Select a Distribution centerpoint — Midgap (the default), From valence band edge, From conduction band edge, or Relative. Then enter the applicable information:
•
Distribution centerpoint Et,0 (SI unit: V). The default is 0 V.
•
Distribution centerpoint (between 0 and 1, 0 being the valence band) 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.
Enter the Continuous energy discretization, number of mesh points Nxdelem (dimensionless). The default is 25.
Enter the Continuous energy discretization, min energy Et,min (SI unit: V). The default is semi.Ev0, the valence band edge in the absence of band gap narrowing.
Enter the Continuous energy discretization, max energy Et,max (SI unit: V). The default is semi.Ec0, the conduction band edge in the absence of band gap narrowing.
Carrier Capture
These settings are the same as for Discrete Energy Level (Domains).