\newcommand\tikzPnJunction[7]{
\begin{tikzpicture}[scale=1.0]

\pgfmathsetmacro{\tkW}{8}               % Total width
\pgfmathsetmacro{\tkH}{5}               % Total height
% left
\pgfmathsetmacro{\tkLx}{0}              % Start
\pgfmathsetmacro{\tkLW}{\tkW*#1}         % Width
\pgfmathsetmacro{\tkLyshift}{#2}       % y-shift
\pgfmathsetmacro{\tkLBendH}{#3}        % Band bending height
\pgfmathsetmacro{\tkLBendW}{\tkLW/4}    % Band bending width
\pgfmathsetmacro{\tkLEv}{0.7+\tkLyshift}% Valence band energy
\pgfmathsetmacro{\tkLEc}{2.3+\tkLyshift}% Conduction band energy
\pgfmathsetmacro{\tkLEV}{4.0+\tkLyshift}% Vacuum energy
\pgfmathsetmacro{\tkLEf}{1.1+\tkLyshift}% Fermi level energy
% right
\pgfmathsetmacro{\tkRx}{\tkW*(1-#4)}       % Start
\pgfmathsetmacro{\tkRW}{\tkW*#4}         % Width
\pgfmathsetmacro{\tkRyshift}{#5}      % y-shift
\pgfmathsetmacro{\tkRBendH}{#6}        % Band bending height
\pgfmathsetmacro{\tkRBendW}{\tkRW/4}    % Band bending width
\pgfmathsetmacro{\tkREv}{0.7+\tkRyshift}% Valence band energy
\pgfmathsetmacro{\tkREc}{2.3+\tkRyshift}% Conduction band energy
\pgfmathsetmacro{\tkREV}{4.0+\tkRyshift}% Vacuum energy
\pgfmathsetmacro{\tkREf}{1.9+\tkRyshift}% Fermi level energy

% materials
\draw[sc p type] (0,0) rectangle (\tkLW,\tkH);
\node at (\tkLW/2,\tkH-0.2) {\GT{p-type}};
\path[sc separate] (\tkRx,0) -- (\tkRx,\tkH);
\path[sc n type] (\tkRx,0) rectangle (\tkW,\tkH);
\node at (\tkRx+\tkRW/2,\tkH-0.2) {\GT{n-type}};
\path[sc separate] (\tkLW,0) -- (\tkLW,\tkH);

\drawAxes

% right bands
\path[sc occupied] (\tkRx, 0) -- \rightBandAuto{}{\tkREv} -- (\tkW, 0) -- cycle;
\draw[sc band con]    \rightBandAuto{$\Econd$}{\tkREc};
\draw[sc band val]    \rightBandAuto{$\Evalence$}{\tkREv};
\draw[sc band vac]    \rightBandAuto{$\Evac$}{\tkREV};
\draw[sc fermi level] \rightBand{$\Efermi$}{\tkREf};
% left bands
\path[sc occupied] (\tkLx, 0) -- \leftBandAuto{}{\tkLEv} -- (\tkLW, 0) -- cycle;
\draw[sc band con]    \leftBandAuto{$\Econd$}{\tkLEc};
\draw[sc band val]    \leftBandAuto{$\Evalence$}{\tkLEv};
\draw[sc band vac]    \leftBandAuto{$\Evac$}{\tkLEV};
\draw[sc fermi level] \leftBand{$\Efermi$}{\tkLEf};

% work functions

\drawDArrow{\tkRx+\tkRW*2/3}{\tkREf}{\tkREV}{$e\Phi_\txn$}
\drawDArrow{\tkRx+\tkRW*1/3}{\tkREc}{\tkREV}{$e\chi_\txn$}
\drawDArrow{\tkLx+\tkLW*2/3}{\tkLEf}{\tkLEV}{$e\Phi_\txp$}
\drawDArrow{\tkLx+\tkLW*1/3}{\tkLEc}{\tkLEV}{$e\chi_\txp$}
% barrier height
% \drawDArrow{\tkRx+\tkRBendW}{\tkREc}{\tkREc+\tkRBendH}{$eU_\text{Bias}$}
% \drawDArrow{\tkRx}{\tkREf}{\tkREc+\tkRBendH}{$e\Phi_\txB$}
#7

\end{tikzpicture}
}
% \tikzPnJunction{1/3}{0}{0}{1/3}{0}{0}{}
% \tikzPnJunction{1/2}{0.4}{-0.4}{1/2}{-0.4}{0.4}{}