EFFECTS OF V III RATIO ON ZN ELECTRICAL-ACTIVITY IN ZN-DOPED INGAALP GROWN BY METALORGANIC CHEMICAL VAPOR-DEPOSITION

The effects of V/II ratio (ratio of molar flow rate of group-V to group-III sources) on Zn electrical activity have been studied for Zn-doped In0.5(Ga(1-x)Al(x))0.5P grown by low-pressure metalorganic chemical vapor deposition. The V/III ratio was varied from 200 to 800. For x = 0.7, the Zn electrical activity decreased gradually when the V/III ratio was reduced. For x = 1.0, it fell off sharply with decreasing V/III ratio. However, the activity did not depend on the V/III ratio for x = 0. The PL peak intensity fell with decreasing V/III ratio for x greater-than-or-equal-to 0.7, while it was almost unchanged for x = 0. Several peaks were observed in the X-ray rocking curve of InGaAlP (x greater-than-or-equal-to 0.7) grown with low V/III ratio. It was found that the V/III ratio had a greater influence on electrical and optical properties of Zn-doped InGaAlP with higher Al composition.