fixes

01_fundamentals.tex

@@ -50,6 +50,6 @@ For doners we have:
 Every semiconductor is neutral,
 which imposes the following condition:
 \begin{equation}
-    P_0-n_0+N_d + N_a = 0
+    P_0-n_0 + N_d - N_a = 0
 \end{equation}
 where $p_0n_0=n_i^2$.
\ No newline at end of file

02_carrier_transport.tex

@@ -8,7 +8,7 @@ but heres the probability distribution:
     f(E) = \frac{1}{1+e^{(E-E_F)/kT}}
 \end{equation}
 
-Electron concentration in conductance band:
+Electron concentration in conduction band:
 \begin{equation}
     n=N_ce^{-(E_c-E_f)/kT}
 \end{equation}
@@ -62,8 +62,11 @@ For the sake of simplicity, let's define mobility for both holes and electrons.
 \subsection{Drift current}
 For the net drift current density slap together velocity, density and charge.
 \begin{equation}
-    label{eq:drift_current}
-    J^{drift} = J_n^{drift}+J_p^{drift} = q(n\mu_n+p\mu_p)E
+    \label{eq:drift_current}
+    \begin{split}
+        J^{drift} &= J_n^{drift}+J_p^{drift} \\
+        &= q(n\mu_n+p\mu_p)E
+    \end{split}
 \end{equation}
 From which we can  find Ohm's law:
 \begin{alignat}{2}