package TFT;
use IniFile;
@ISA = qw(IniFile);

#公開したいサブルーチン
@EXPORT = qw();

use strict;
#use warnings;

use Math::Matrix;
use Math::MatrixReal;
use PDL::Opt::Simplex;
use Sci::Material;

use Deps;
use Utils;
use JFile;

use CSV;
use Sci qw($kB $e $e0);

#===============================================
# 大域変数
#===============================================

#============================================================
#　変数等取得関数
#============================================================

#============================================================
#　コンストラクタ、デストラクタ
#============================================================
sub new
{
	my ($module, $app) = @_;

	my $self = IniFile->new('', 0, 0);
	my $this = bless $self, ref($module) || $module;
	$this->SetApplication($app) if($app);
	return $this;
}

sub DESTROY
{
	my $this = shift;
}

#============================================================
#　一般関数
#============================================================
sub SetParameters
{
	my ($this, %args) = @_;
	
	Utils::MergeHash($this, \%args);
}

sub PrepareForCalculation
{
	my ($this) = @_;

	my $T     = $this->{T};
	my $W     = $this->{W};
	my $L     = $this->{L};
	my $Nes   = $this->{Nes}  * 1.0e6;
	my $Epss  = $this->{Epss} * $e0;
	my $uFE   = $this->{uFE}  * 1.0e-4;
	my $material = new Material;
	$this->{Cox} = $material->CalCapacitance($this->{Epsg}, 0.01*0.01, $this->{dg}*1.0e-9)
		if(!defined $this->{Cox}); # F/cm2
	my $Cox   = $this->{Cox}  * 1.0e4;
#	my $S     = $this->{S};
#	my $VB    = $this->{VB};
#	my $VFB   = $this->{VFB};
#	my $Vth   = $this->{Vth};

	$this->{K}   = $W / $L * $uFE * $Cox;
	$this->{Kth} = 2.0 / 3.0 * sqrt(abs(2 * $Epss * $e *  $Nes)) / $Cox;
	$this->{Ks}  = $Epss * $e *  $Nes / $Cox / $Cox;
	$this->{Ks2} = 2.0 * $Cox * $Cox / $Epss / $e / $Nes;
}

sub SetPolarity
{
	my ($this, $iPolarity) = @_;
	return $this->{Polarity} = $iPolarity;
}

sub PinchoffVds
{
	my ($this, $Vgs) = @_;

	my $VFB    = $this->{VFB};
	my $VB     = $this->{VB};
	my $c      = 1.0 + $this->{Ks2} * abs($Vgs - $VFB);
	my $Vpinch = $Vgs - $VFB - 2.0*$VB * $this->{Ks} * (1.0 - sqrt($c));
	return $Vpinch;
}

sub PinchoffVdsAtSmallVds
{
	my ($this, $Vgs) = @_;

	my $Vth    = $this->{Vth};
	my $Vpinch = $Vgs - $Vth;
	return $Vpinch;
}

sub TFTIds
{
	my ($this, $Vgs, $Vds) = @_;
	if($this->{Polarity} > 0) {
		return $this->nTFTIds($Vgs, $Vds);
	}
	return $this->pTFTIds($Vgs, $Vds);
}

sub nTFTIds
{
	my ($this, $Vgs, $Vds) = @_;
	return $this->IdsByModel($Vgs, $Vds);
}

sub pTFTIds
{
	my ($this, $Vgs, $Vds) = @_;
	return $this->IdsByModel(-$Vgs, $Vds);
}

sub Ids
{
	my ($this, $Vgs, $Vds) = @_;

	my $VFB  = $this->{VFB};
	my $VB   = $this->{VB};
	my $K    = $this->{K};
	my $Veff = $Vgs - $VFB - 2.0*$VB - 0.5*$Vds;
	return 0.0 if($Veff < 0.0);
	my $a    = $Veff * $Vds;
	my $b    = abs($Vds + 2.0 * $VB)**1.5 - abs(2.0 * $VB)**1.5;
	my $Ids  = $K * ($a - $this->{Kth} * $b);
	return $Ids;
}

sub IdsAtSmallVds
{
	my ($this, $Vgs, $Vds) = @_;

	my $Vth  = $this->{Vth};
	my $K    = $this->{K};
	my $Veff = $Vgs - $Vth;
	return 0.0 if($Veff < 0.0);
	my $Ids = $K * ($Veff * $Vds - $Vds * $Vds * 0.5);
	return $Ids;
}

sub IdsByModel
{
	my ($this, $Vgs, $Vds) = @_;

	my $Model = $this->{Model};

	my $Vpinch;
	if($Model eq 'Exact') {
		$Vpinch = $this->PinchoffVds($Vgs);
	}
	else {
		$Vpinch = $this->PinchoffVdsAtSmallVds($Vgs);
	}
	my $Ipinch= $this->Ids($Vgs, $Vpinch);
#print "Vgs=$Vgs  Vp=$Vpinch, Ip=$Ipinch  Vth=$this->{Vth}\n";

	my $Ids;
	if($Model eq 'Exact') {
		if($Vds > $Vpinch) {
			$Ids = $this->Ids($Vgs, $Vpinch);
		}
		else {
			$Ids = $this->Ids($Vgs, $Vds);
		}
	}
	else {
		if($Vds > $Vpinch) {
			$Ids = $this->IdsAtSmallVds($Vgs, $Vpinch);
		}
		else {
			$Ids = $this->IdsAtSmallVds($Vgs, $Vds);
		}
	}

	return $Ids;
}

sub FermiDiracFunction
{
	my ($E, $T, $EF, $C0, $Wa) = @_; # eV
#print "E=$E EF=$EF kB=$kB T=$T e=$e Wa=$Wa\n";
	return $C0 / (1.0 + exp(($E-$EF)/($kB*$T/$e+$Wa)));
}


1;