Enhanced Sheet Charge Density in DIBS Grown CdO Alloyed ZnO Buffer Based Heterostructure

In this letter, we report on achieving significantly high (similar to 6x) sheet charge density (n(s)) in MgZnO/CdZnO heterostructure, as compared with that in MgZnO/ZnO, at lower Mg (<= 0.15) compositions in barrier MgZnO layer, with both heterostructures grown by dual ion beam sputtering technique. Buffer CdZnO and barrier MgZnO layers are probed separately to investigate carrier density in defect prone sputtered layers. Capacitance-voltage measurement and temperature-dependent Hall measurement confirm the presence of quantum confined carrier density at barrier-buffer interface, suggesting that the enhancement in carrier densities in the heterostructure over individual layers is probably due to the formation of 2-D electron gas (2-DEG).