Update 14_doping_and_devices_solutions.md

src/14_doping_and_devices_solutions.md

@@ -83,10 +83,11 @@ $$ I_s(T) \propto e^{-E_{gap}/k_BT}$$
 
 ![](figures/diagram_14.png)
 
+
 ### Subquestion 2
 This a "particle in a box" problem.
-$$-\frac{\hbar^2}{2m_e^{\ast}} \frac{\partial^2 \Psi_e(z)}{\partial z^2} = (E-U_0)\Psi_e $$
-$$-\frac{\hbar^2}{2m_h^{\ast}} \frac{\partial^2 \Psi_h(z)}{\partial z^2} = (E-U_0)\Psi_h $$
+$$-\frac{\hbar^2}{2m_e^{\ast}} \frac{\partial^2 \Psi_e(z)}{\partial z^2} = (E_e-E_c)\Psi_e $$
+$$-\frac{\hbar^2}{2m_h^{\ast}} \frac{\partial^2 \Psi_h(z)}{\partial z^2} = (E_v-E_h)\Psi_h $$
 
 
 ### Subquestion 3