CHARACTERIZATION OF P-TYPE ZNSE

Lithium-doped ZnSe has been grown on (100) GaAs by molecular beam epitaxy. The epitaxial layers are p-type with net acceptor concentrations (N A-ND) as high as 8×1016 cm -3 - the highest ever reported for molecular beam epitaxial ZnSe. Room temperature ac measurements show resistivities as low as 2.9 Ω cm. Higher Li concentrations give rise to self-compensation and a decrease in NA-ND. The details of the electrical and optical characterization of these layers are presented. Rudimentary blue light emitting pn junction diodes have been fabricated. While these devices show dominant blue emission (463 nm) at room temperature, large turn-on voltages indicate that the p-ZnSe/p-GaAs interface presents a large barrier to hole transport. Moreover, we find that difficulty in making device-quality ohmic contacts to p-ZnSe is the next major obstacle to the fabrication of efficient blue light emitting diodes.