Update 14_doping_and_devices_solutions.md

src/14_doping_and_devices_solutions.md

@@ -49,8 +49,9 @@ $$ n_A^{\ast} = N_A (1-\frac{1}{e^({E_F-E_A})/k_BT+1})$$
 $\ast$ indicates non-ionized concentrations.
 ### Subquestion 3
 
-Use Germianium Fermi Energy at room temperature and perform the
-[key algorithm of describing the state of a semiconductor](13_semiconductors/#part-1-pristine-semiconductor)
+??? hint "how?"
+    Use Germianium Fermi Energy at room temperature and perform the
+    [key algorithm of describing the state of a semiconductor](13_semiconductors/#part-1-pristine-semiconductor)
 
 ## Exercise 3: Performance of a diode