/*********************************************************************
   C2025_07_08    by Yoshiaki Hagiwara, hagiwara@ofc.sojo-u.ac.jp
**********************************************************************

****************************************
        重要な関係式
****************************************

EG=1.11 eV;

kT=0.0259 eV;

Esi=648 e/(V・μm);

NC=10400000 e/(μm)**3;

NV=28000000e/(μm)**3; 

*************************************************************

 { DP = Nv exp( - VBP/kT ) - Nc exp( (VBP-EG)/kT );}

 { DN = Nc exp( - VBN/kT ) - Nv exp( (VBN-EG)/kT );}

 { EG = Vout + VBP + VBN + VB ; }  

 { DPN = (DP*DN)/( DP + DN ); }

 { WD = sqrt( 2*Esi*VB/DPN ) ; }

*************************************************************

（１） if { DP=0; }, { VBPP=(EG+kT*ln(NV/NC))/2=0.567826 ;}

（２） if { DN=0; }, { VBNN=(EG+kT*ln(NC/NV))/2=0.542174 ;}

*************************************************************







****************************** C-Code ****************************/
 
#include <stdio.h> 
#include <math.h>


double EG=1.11,kT=0.0259,Esi=648,NC=10400000,NV=28000000;

double VBPP=0.567826,VBNN=0.542174;

double VBN1,VBN2,VBN3,DN1,DN2,DN3;

double VBP1,VBP2,VBP3,DP1,DP2,DP3;

double Vout,DN,DP,DPN,VBN,VBP,VB,WD,WDN;


int k,j,i,iDP,jDN;

char c;

FILE *fpBB;

/****************************************************/

void Obtain_VBN( void ) {


k=0;

VBN1=0;

VBN2=VBNN;

NEXT_VBN:

VBN3=(VBN1+VBN2)/2;

DN1 = NC*exp( - VBN1/kT ) - NV*exp( (VBN1-EG)/kT );

DN2 = NC*exp( - VBN2/kT ) - NV*exp( (VBN2-EG)/kT );

DN3 = NC*exp( - VBN3/kT ) - NV*exp( (VBN3-EG)/kT );

if( DN3 < DN ) VBN2=VBN3; 

if( DN3 > DN ) VBN1=VBN3;

k=k+1;

if(k<100) goto NEXT_VBN;

VBN=VBN3; }


/****************************************************/


void Obtain_VBP( void ) {


k=0;

VBP1=0;

VBP2=VBPP;

NEXT_VBP:

VBP3=(VBP1+VBP2)/2;

DP1 = NV*exp( - VBP1/kT ) - NV*exp( (VBP1-EG)/kT );

DP2 = NV*exp( - VBP2/kT ) - NV*exp( (VBP2-EG)/kT );

DP3 = NV*exp( - VBP3/kT ) - NV*exp( (VBP3-EG)/kT );

if( DP3 < DP ) VBP2=VBP3; 

if( DP3 > DP ) VBP1=VBP3;

k=k+1;

if(k<100) goto NEXT_VBP;

VBP=VBP3; }


/****************************************************/


void main(void){

fpBB=fopen( "BB.txt","w");


Vout=0;


NEXT_Vout:

 printf(     "\n\n  Vout = %f \n\n", Vout);

fprintf(fpBB,"\n\n  Vout = %f \n\n", Vout);



iDP=100;

i=1;

NEXT_DP:

DP=iDP; 

Obtain_VBP( );

 printf(     "\n\n\n  *********************************************** \n");

fprintf(fpBB,"\n\n\n  *********************************************** \n");


 printf(     "\n  DP = %d  \n",iDP);

fprintf(fpBB,"\n  DP = %d  \n",iDP);

 printf(     "\n\n\n  *********************************************** \n");

fprintf(fpBB,"\n\n\n  *********************************************** \n");


jDN=iDP; j=1;

NEXT_DN:

DN=jDN;

Obtain_VBN( );

VB=EG-Vout-VBP-VBN;

if(VB<0) goto JUMP;

DPN=DP*DN/(DP+DN);

WD=sqrt(2*Esi*VB/DPN);

WDN=DP*WD/(DP+DN);

 printf(     "\n  WD=%f  WDN=%f    DN/DP=%d \n",WD,WDN,jDN/iDP);

fprintf(fpBB,"\n  WD=%f  WDN=%f    DN/DP=%d \n",WD,WDN,jDN/iDP);

JUMP: 

j=j+1;

jDN=jDN*10;

if(j<6) goto NEXT_DN;

i=i+1;

 printf(     "\n  *********************************************** \n\n\n");

fprintf(fpBB,"\n  *********************************************** \n\n\n");



iDP=iDP+100;

if(i<11) goto NEXT_DP;


Vout=Vout+0.1;

if(Vout<0.6) goto NEXT_Vout;








/****************************************************/


c=getchar( ); 

if(c=='!') printf("\n\n Good-bye !!");


fclose(fpBB); }



/******************* End of C-code *******************/