\documentclass[tikz,border=10pt]{standalone}
\usepackage{luatexja}
\begin{document}
\begin{tikzpicture}
\draw(-0.35,-0.75)node{電極};
\draw[densely dotted](0.66,0)--(0.66,0.5)
(1.32,0)--(1.32,0.5);
\draw[<->](0.66,0.250)--(1.32,0.250);
\draw(1,0.25)arc[x radius=0.5,y radius=0.5,
start angle=180,end angle=90];
\draw(2,0.75)node{空乏層};
\draw(0.75,1)--(-1.5,1)--(-1.5,-2)--(3,-2)--(3,1)--(1,1);
\draw(0.75,1.5)--(0.75,0.5);
\draw(1,1.25)--(1,0.75);
\fill[ball color=pink!80!magenta]
(1.32,0)--(1.32,-4)--(2,-4)--(2,0);
\fill[white,opacity=0.9](0.66,0)--(0.66,-4)--(2,-4)--(2,0);
\fill[ball color=cyan](0,0)--(0.66,0)--(0.66,-4)--(0,-4);
\fill[white,opacity=0.9](0,0)--(0.66,0)--(0.66,-4)--(0,-4);
\fill[ball color=gray!50!white]
(0,-1)--(-0.5,-1)--(-0.5,-3)--(0,-3);
\draw(0,-1)--(-0.5,-1)--(-0.5,-3)--(0,-3);
\draw(0,0)--(2,0)--(2,-4)--(0,-4)--cycle;
\draw(0.66,0)--(0.66,-4);
\draw(1.32,0)--(1.32,-4);
\foreach \i in {0,...,6} {
\pgfmathsetmacro{\y}{-1.25 - 0.25*\i}
\draw (-0.25,\y) node {$+$};
}
\draw(1.65,-2.5)node{p-Si};
\draw(0.36,-3.5)node{SiO$_2$};
\foreach \x in {0.85,1.15} {
\foreach \i in {0,...,6} {
\pgfmathsetmacro{\y}{-1.25 - 0.25*\i}
\fill[ball color=cyan!50!blue] (\x,\y) circle (0.125);
\fill[white,opacity=0.8] (\x,\y) circle (0.125);
}
}
\foreach \x in {0.85,1.15} {
\foreach \i in {0,...,6} {
\pgfmathsetmacro{\y}{-1.25 - 0.25*\i}
\draw (\x,\y) circle (0.125);
}
}
\foreach \i in {0,...,6} {
\pgfmathsetmacro{\y}{-1.25 - 0.25*\i}
\draw (1,\y) node {$--$};
}
\foreach \x/\y/\label in
{ -0.25/-3.25/M, 0.375/-4.25/O, 1.375/-4.25/S}
\draw (\x,\y) node {\label};
\end{tikzpicture}
\end{document}