Update src/14_doping_and_devices.md

src/14_doping_and_devices.md

@@ -258,17 +258,17 @@ Consider a pn-junction diode as follows
 
 The current generated by the pn diode as a function of applied bias voltage is given by 
 
-$$ I(V) = J_s(T)\left(e^{\frac{eV}{kT}}-1\right)$$
+$$ I(V) = I_s(T)\left(e^{\frac{eV}{kT}}-1\right)$$
 
-where $J_s(T)$ is the current flowing through a diode when it is reverse biased i.e. the positive terminal of battery is connected to n-type semiconductor and the negative terminal to p-type. $I_0$ is nearly independent of the applied bias voltage (V) but varies as a function of temperature (T).
+where $I_s(T)$ is the current flowing through a diode when it is reverse biased i.e. the positive terminal of battery is connected to n-type semiconductor and the negative terminal to p-type. $I_s(T)$ is nearly independent of the applied bias voltage (V) but varies as a function of temperature (T). 
 
 <Add I-V plot of pn diode from simon's book>
 
-1. Write down two possible scenarios by which a pn diode generates current in reverse biased condition.
+1. Write down two possible scenarios by which a pn diode generates a small current in the reverse biased condition.
 2. How does the temperature affect the diode performance in the two scenarios written in 3.1.
-3. Sketch a plot of saturation current as a function of temperature
-4. Explain the dominant contribution to current in forward biased situation.
-5. Does two intrinsic semiconductors joined together make a diode?
+3. Sketch a plot of saturation current as a function of temperature T.
+4. Explain the dominant contribution to current generation in the forward biased condition.
+5. Does two intrinsic semiconductors joined together functions as a diode?
 
 ### Exercise 4: Quantum well heterojunction in detail
 A quantum well is formed from a layer of $GaAs$ of thickness $L$, surrounded by layers of $Al_{x}Ga_{1−x}As$.