Fabrication of tunable n-Zn1-xCdxO/p-GaN heterojunction light-emitting diodes

Zn_1-xCd_xO films with different Cd contents obtained by controlling the growth oxygen pressure (O_p) were deposited on both c-sapphire (Al₂O₃) substrates and p-GaN substrates, by means of the pulsed laser deposition (PLD) method. Photoluminescence (PL) measurement revealed that the variation of O_p influenced the amount of Cd doping into Zn_1-xCd_xO films deposited on Al₂O₃, leading tunable luminescence from the ultraviolet (UV) to blue emission extended to the green band. Then all the fabricated n-Zn_1-xCd_xO/p-GaN heterojunction possessed good ohmic contacts and exhibited typical rectifying characteristic of the diode. Indeed, the high luminescence from the ZnCdO layer could be attained by inserting a MgO insulator to the heterojunction interface. The fabrication of tunable n-Zn_1-xCd_xO/p-GaN heterojunction light-emitting diodes is available which was supported by the results of electroluminescence (EL) experiment.