Method for producing light emitting semiconductor device
Method for producing a light emitting semiconductor device comprising a zinc magnesium oxide based layer as active layer, wherein the zinc magnesium oxide based layer comprises an aluminum doped zinc magnesium oxide layer having the nominal composition Zn 1-x Mg x O with 1-350 ppm Al, wherein x is in the range of 0<x≦0.3. The invention further provides a method for the production of such aluminum doped zinc magnesium oxide, the method comprising heat treating a composition comprising Zn, Mg and Al with a predetermined composition at elevated temperatures, and subsequently annealing the heat treated composition to provide said aluminum doped zinc magnesium oxide.
1. A method for producing a light emitting semiconductor device, the method comprising:
providing a support,
forming a stack on the support,
wherein the stack comprises a cathode, a semiconductor layer comprising an emissive material configured to emit in the range of 300-900 nm, an insulating layer, and an anode,
wherein the cathode is in electrical contact with the semiconductor layer,
wherein the anode is in electrical contact with the insulating layer,
wherein the insulating layer has a thickness in the range of up to 50 nm,
wherein the semiconductor layer comprises aluminum doped zinc magnesium oxide layer having 1-350 ppm Al.
2. The method according to claim 1 , further comprising:
forming the cathode on the support,
forming the semiconductor layer on the cathode,
forming the insulating layer on the semiconductor layer,
forming the anode on the insulating layer,
followed by annealing the stack,
wherein annealing is performed at a temperature in the range of 400-1100° C.
3. The method according to claim 1 , wherein the emissive material has a conduction band at CBp eV and a valence band at VBp eV from the vacuum level, with CBp>VBp,
wherein the insulating layer has a conduction band at CBb eV and a valence band at VBb eV from the vacuum level, with CBb>VBb,
wherein CBb>CBp and wherein VBb≦VBp+1.5 eV.
4. The method according to claim 1 , wherein the semiconductor layer comprises an emissive material selected from the group consisting of ZnO, (Zn,Mg)O, ZnS, ZnSe, CdO, CdS, CdSe, and doped variants of any of these, and wherein the insulating layer is selected from the group consisting of SiO 2 , MgO, SrTiO 3 , ZrO 2 , HfO 2 , and Y 2 O 3 .
5. The method according to claim 1 , wherein the semiconductor layer comprises an emissive material,
wherein the formation of the semiconductor layer comprises a deposition technique selected from the group consisting of pulsed laser deposition (PLD) and radio frequency (RF) sputtering,
wherein the semiconductor layer has the nominal composition Zn 1-x Mg x O with 1-350 ppm Al, wherein x is in the range of 0<x≦0.3.
6. The method according to claim 1 , wherein the semiconductor layer is polycrystalline.