From 6ddd1384535f0e4ee9e13885212480cdd646e11d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Simon=20Th=C3=BCr?= <thuer.simon@hotmail.com> Date: Fri, 7 Apr 2023 23:07:28 +0200 Subject: [PATCH] rm useless section, use only sss instead of ss2 --- 02_carrier_transport.tex | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/02_carrier_transport.tex b/02_carrier_transport.tex index eb80b64..963e45b 100644 --- a/02_carrier_transport.tex +++ b/02_carrier_transport.tex @@ -26,11 +26,8 @@ Which gives us the useful relation: n_i = \sqrt{N_cN_v}e^{-(E_c-E_v)/2kT} = \sqrt{N_cN_v}e^{-E_g/2kT} \end{equation} -\subsubsection{Temperature dependance} -Looking at the equations in \autoref{label:sec:fermi} we see that the higher the temperature or the lower the band-gap, the more electrons and holes are created. -\subsection{Carrier transport} -\subsubsection{Thermal equilibrium} +\subsection{Behaviour in thermal equilibrium} \begin{align} \lambda & \equiv \text{mean free path} [cm] \\ \tau_c & \equiv \text{mean time between collisions} [s^{-1}] \\ @@ -39,7 +36,7 @@ Looking at the equations in \autoref{label:sec:fermi} we see that the higher the \end{align} -\subsubsection{Drift velocity} +\subsection{Drift velocity} Quick electromag recap: (for holes use + and $m_p$) \begin{align} F & = -qE \\ @@ -51,7 +48,7 @@ Average drift velocity: v_d = \pm \frac{qE\tau_c}{2m_{n,p}} \end{equation} -\subsubsection{Mobility} +\subsection{Mobility} For the sake of simplicity, let's define mobility for both holes and electrons. (These values are usually found in diagrams.) \begin{align} @@ -61,7 +58,7 @@ For the sake of simplicity, let's define mobility for both holes and electrons. \mu_n & >_mu_p \end{align} -\subsubsection{Drift current} +\subsection{Drift current} For the net drift current density slap together velocity, density and charge. \begin{equation} label{eq:drift_current} @@ -79,7 +76,7 @@ Which gives us different resistances for n and p type semiconductors. \end{align} -\subsubsection{Diffusion current} +\subsection{Diffusion current} If there is a concentration gradient, the carriers will diffuse to equalize the concentration. Here flux $F \ [cm^{-2}s^{-1}]$ is the number of electrons/holes per unit area per unit time. \begin{align} F_n & = -D_n\frac{\mathrm{d} n}{\mathrm{d} x} \\ @@ -94,12 +91,12 @@ Which gives us the diffusion current density: \end{align} -\subsubsection{Einstein relation between mobility and diffusion coefficient} +\subsection{Einstein relation between mobility and diffusion coefficient} \begin{equation} \frac{D_n}{\mu_n} = \frac{D_p}{\mu_p} = \frac{kT}{q^2} \end{equation} -\subsubsection{Total current} +\subsection{Total current} \begin{alignat}{2} J_{total} & =J_n+J_p & & \\ J_n & =J_n^{drift}+J_n^{diff} & & =qn\mu_nE+qD_n\frac{\mathrm{d} n}{\mathrm{d} x} \\ -- GitLab