<P>both p- and n-side are very lightly doped. both p- and 11-side are HEAVILY doped. p-side is heavily doped but n-side is lightly doped. p-side is ilightly doped but n-side is heavily doped.
Solution :In a zener diode both p-side and n-side of p-n JUNCTION are heavily doped so that breakeven VOLTAGE is about 5 V.