src/material/Ge/Ge_gen.cc

   1 /*****************************************************************************/
   2 /*                                                                           */
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   4 /*            8                8                8                            */
   5 /*           8                 8                8                            */
   6 /*           8                  88888888         88888888                    */
   7 /*           8      8888                8                8                   */
   8 /*            8       8                 8                8                   */
   9 /*              888888         888888888        888888888                    */
  10 /*                                                                           */
  11 /*       A Two-Dimensional General Purpose Semiconductor Simulator.          */
  12 /*                                                                           */
  13 /*  GSS material database Version 0.4                                        */
  14 /*  Last update: Feb 17, 2006                                                */
  15 /*                                                                           */
  16 /*  Gong Ding                                                                */
  17 /*  gdiso@ustc.edu                                                           */
  18 /*  NINT, No.69 P.O.Box, Xi'an City, China                                   */
  19 /*                                                                           */
  20 /*****************************************************************************/
  21 //
  22 // Material Type: Ge
  23
  24 #include "PMI.h"
  25
  26 class GSS_Ge_Avalanche : public PMIS_Avalanche
  27 {
  28 private:
  29   PetscScalar N_IONIZA; // The constant term in the multiplicative prefactor of the electron ionization coefficient.
  30   PetscScalar ECN_II;   // The critical electric field used in the exponential factor of the electron ionization coefficient.
  31   PetscScalar EXN_II;   // The exponent of the ratio of the critical electrical field to the local electric field.
  32   PetscScalar P_IONIZA; // The constant term in the multiplicative prefactor of the hole ionization coefficient.
  33   PetscScalar ECP_II;   // The critical electric field used in the exponential factor of the hole ionization coefficient.
  34   PetscScalar EXP_II;   // The exponent of the ratio of the critical electrical field to the local electric field.
  35   PetscScalar N_ION_1;  // The coefficient multiplying T in the multiplicative prefactor of the electron ionization coefficient.
  36   PetscScalar N_ION_2;  // The coefficient multiplying T^2 in the multiplicative prefactor of the electron ionization coefficient.
  37   PetscScalar P_ION_1;  // The coefficient multiplying T in the multiplicative prefactor of the hole ionization coefficient.
  38   PetscScalar P_ION_2;  // The coefficient multiplying T^2 in the multiplicative prefactor of the hole ionization coefficient.
  39   //// Impact Ionization Model Depending on Lattice Temperature.
  40   PetscScalar LAN300;   // Energy free path for electrons at 300 K, used for the impact ionization model depending on lattice temperature.
  41   PetscScalar LAP300;   // Energy free path for holes at 300 K, used for the impact ionization model depending on lattice temperature.
  42   PetscScalar OP_PH_EN; // Mean optical phonon energy used for the impact ionization model depending on lattice temperature.
  43   //
  44   PetscScalar ElecTauw;
  45   PetscScalar HoleTauw;
  46   PetscScalar T300    ;
  47
  48   void  Avalanche_Init()
  49   {
  50     N_IONIZA  =  1.550000e+07/cm;
  51     ECN_II    =  0.000000e+00*V/cm;
  52     EXN_II    =  1.000000e+00;
  53     P_IONIZA  =  1.000000e+07/cm;
  54     ECP_II    =  0.000000e+00*V/cm;
  55     EXP_II    =  1.000000e+00;
  56     N_ION_1   =  0.000000e+00/cm*K;
  57     N_ION_2   =  0.000000e+00/cm*K*K;
  58     P_ION_1   =  0.000000e+00/cm*K;
  59     P_ION_2   =  0.000000e+00/cm*K*K;
  60     LAN300    =  6.888250e-07*cm;
  61     LAP300    =  8.395050e-07*cm;
  62     OP_PH_EN  =  3.700000e-02*eV;
  63
  64     ElecTauw  = 2e-13*s;
  65     HoleTauw  = 2e-13*s;
  66     T300      = 300.0*K;
  67   }
  68 public:
  69   //---------------------------------------------------------------------------
  70   // Electron Impact Ionization rate for DDM
  71   PetscScalar ElecGenRate (const PetscScalar &Tl,const PetscScalar &Ep,const PetscScalar &Eg) const
  72   {
  73     if (Ep < 1e4*V/cm)
  74     {
  75       return 0;
  76     }
  77     else
  78     {
  79       PetscScalar alpha = N_IONIZA + N_ION_1*Tl + N_ION_2*Tl*Tl;
  80       PetscScalar L=LAN300*tanh(OP_PH_EN/(2*kb*Tl));
  81       return alpha*exp(-pow(Eg/(e*L)/Ep,EXN_II));
  82     }
  83   }
  84   AutoDScalar ElecGenRate (const AutoDScalar &Tl,const AutoDScalar &Ep,const AutoDScalar &Eg) const
  85   {
  86     if (Ep < 1e4*V/cm)
  87     {
  88       return 0;
  89     }
  90     else
  91     {
  92       AutoDScalar alpha = N_IONIZA + N_ION_1*Tl + N_ION_2*Tl*Tl;
  93       AutoDScalar L = LAN300*tanh(OP_PH_EN/(2*kb*Tl));
  94       AutoDScalar Ecrit = Eg/(e*L);
  95       return alpha*exp(-pow(Ecrit/Ep,EXN_II));
  96     }
  97   }
  98
  99   //---------------------------------------------------------------------------
 100   // Hole Impact Ionization rate for DDM
 101   PetscScalar HoleGenRate (const PetscScalar &Tl,const PetscScalar &Ep,const PetscScalar &Eg) const
 102   {
 103     if (Ep < 1e4*V/cm)
 104     {
 105       return 0;
 106     }
 107     else
 108     {
 109       PetscScalar alpha = P_IONIZA+P_ION_1*Tl+P_ION_2*Tl*Tl;
 110       PetscScalar L = LAP300*tanh(OP_PH_EN/(2*kb*Tl));
 111       return alpha*exp(-pow(Eg/(e*L)/Ep,EXP_II));
 112     }
 113   }
 114   AutoDScalar HoleGenRate (const AutoDScalar &Tl,const AutoDScalar &Ep,const AutoDScalar &Eg) const
 115   {
 116     if (Ep < 1e4*V/cm)
 117     {
 118       return 0;
 119     }
 120     else
 121     {
 122       AutoDScalar alpha = P_IONIZA+P_ION_1*Tl+P_ION_2*Tl*Tl;
 123       AutoDScalar L = LAP300*tanh(OP_PH_EN/(2*kb*Tl));
 124       AutoDScalar Ecrit = Eg/(e*L);
 125       return alpha*exp(-pow(Ecrit/Ep,EXP_II));
 126     }
 127   }
 128
 129   //---------------------------------------------------------------------------
 130   // Electron Impact Ionization rate for EBM
 131   PetscScalar ElecGenRateEBM (const PetscScalar &Tn,const PetscScalar &Tl,const PetscScalar &Eg) const
 132   {
 133     if (fabs(Tn - Tl)<1*K)
 134     {
 135       return 0;
 136     }
 137     else
 138     {
 139       PetscScalar vsat = (2.4e7*cm/s)/(1+0.8*exp(Tl/(2*T300)));
 140       PetscScalar L = LAN300*tanh(OP_PH_EN/(2*kb*Tl));
 141       PetscScalar Ecrit = Eg/(e*L);
 142       PetscScalar uc   = 2*vsat*ElecTauw/3*Ecrit;
 143       PetscScalar ut   = kb/e*(Tn-Tl);
 144       return N_IONIZA/e*exp(-pow(uc/ut,EXN_II));
 145     }
 146   }
 147   AutoDScalar ElecGenRateEBM (const AutoDScalar &Tn,const AutoDScalar &Tl,const AutoDScalar &Eg) const
 148   {
 149     if (fabs(Tn - Tl)<1*K)
 150     {
 151       return 0;
 152     }
 153     else
 154     {
 155       AutoDScalar vsat = (2.4e7*cm/s)/(1+0.8*exp(Tl/(2*T300)));
 156       AutoDScalar L = LAN300*tanh(OP_PH_EN/(2*kb*Tl));
 157       AutoDScalar Ecrit = Eg/(e*L);
 158       AutoDScalar uc   = 2*vsat*ElecTauw/3*Ecrit;
 159       AutoDScalar ut   = kb/e*(Tn-Tl);
 160       return N_IONIZA/e*exp(-pow(uc/ut,EXN_II));
 161     }
 162   }
 163
 164   //---------------------------------------------------------------------------
 165   // Hole Impact Ionization rate for EBM
 166   PetscScalar HoleGenRateEBM (const PetscScalar &Tp,const PetscScalar &Tl,const PetscScalar &Eg) const
 167   {
 168     if (fabs(Tp - Tl)<1*K)
 169     {
 170       return 0;
 171     }
 172     else
 173     {
 174       PetscScalar vsat = (2.4e7*cm/s)/(1+0.8*exp(Tl/(2*T300)));
 175       PetscScalar L = LAN300*tanh(OP_PH_EN/(2*kb*Tl));
 176       PetscScalar Ecrit = Eg/(e*L);
 177       PetscScalar uc   = 2*vsat*HoleTauw/3*Ecrit;
 178       PetscScalar ut   = kb/e*(Tp-Tl);
 179       return P_IONIZA/e*exp(-pow(uc/ut,EXP_II));
 180     }
 181   }
 182   AutoDScalar HoleGenRateEBM (const AutoDScalar &Tp,const AutoDScalar &Tl,const AutoDScalar &Eg) const
 183   {
 184     if (fabs(Tp - Tl)<1*K)
 185     {
 186       return 0;
 187     }
 188     else
 189     {
 190       AutoDScalar vsat = (2.4e7*cm/s)/(1+0.8*exp(Tl/(2*T300)));
 191       AutoDScalar L = LAN300*tanh(OP_PH_EN/(2*kb*Tl));
 192       AutoDScalar Ecrit = Eg/(e*L);
 193       AutoDScalar uc   = 2*vsat*HoleTauw/3*Ecrit;
 194       AutoDScalar ut   = kb/e*(Tp-Tl);
 195       return P_IONIZA/e*exp(-pow(uc/ut,EXP_II));
 196     }
 197   }
 198
 199
 200 //----------------------------------------------------------------
 201 // constructor and destructor
 202 public:
 203   GSS_Ge_Avalanche(const PMIS_Environment &env):PMIS_Avalanche(env)
 204   {
 205     Avalanche_Init();
 206   }
 207   ~GSS_Ge_Avalanche()
 208   {
 209   }
 210
 211 }
 212 ;
 213
 214 extern "C"
 215 {
 216   PMIS_Avalanche* PMIS_Ge_Avalanche_Default (const PMIS_Environment& env)
 217   {
 218     return new GSS_Ge_Avalanche(env);
 219   }
 220 }