Laser diode with electron and hole confinement and barrier layers
AssigneeMonda & Associates
InventorHiroshi Iwata
Life of this patent
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Abstract
A laser diode suitable for blue-green light emission utilizing type II heterojuctions of II-VI compound semiconductors. The laser diode comprises a layer 24 for confining electrons, a layer 26 for confining holes, and a quantum well layer which is formed bewteen the electron confinement layer 24 and the hole confinement layer 26 and allows the confined electrons and holes to recombine therein. The laser also comprises an electron barrier layer 23 and a hole barrier layer 27 for preventing diffusion of the electrons and holes beyond the barriers. The light emitted by the recombination is confined between the n-cladding layer 22 and a p-cladding layer 28.
Claims17
A laser diode, comprising a semiconductor substrate and compound semiconductor layers lattice-matched with said substrate in a sequence of:
- a p-cladding layer;
- a hole barrier layer with p-type conduction forming an interface with said p-cladding layer;
- a hole confinement layer forming an interface with said hole barrier layer, for confining therein holes;
- an electron confinement layer forming an interface with said hole confinement layer, for confining therein electrons;
- an electron barrier layer with n-type conduction forming an interface with said electron confinement layer;
- and
- an n-cladding layer forming an interface with said electron barrier layer,
- wherein said electron confinement layer and said hole confinement layer form a type II heterojunction,
- wherein said laser diode has a band line-up such that:
- a potential for holes (hole potential) is low in said hole confinement layer and a potential for electrons (electron potential) is low in said electron confinement layer;
- said hole potential is higher in said hole barrier layer than in said hole confinement layer;
- and
- said electron potential is higher in said electron barrier layer than in said electron confinement layer;
- and
- wherein said p-cladding layer and said n-cladding layer have refractive indices smaller than at least one of refractive indices of said hole confinement layer and said electron confinement layer.
A laser diode, comprising a semiconductor substrate and epitaxial layers lattice matched with said substrate in a sequence of:
- an n-cladding layer;
- an electron barrier layer with n-type conduction forming an interface with said n-cladding layer;
- an electron confinement layer forming an interface with said electron barrier layer, for confining electrons therein;
- a quantum well layer forming an interface with said electron confinement layer;
- a hole confinement layer forming an interface with said quantum well layer, for confining holes therein;
- a hole barrier layer with p-type conduction forming an interface with said hole confinement layer;
- and
- a p-cladding layer forming an interface with said hole barrier layer,
- wherein said sequence of layers have a type II band line-up such that:
- a potential for holes (hole potential) is low in said hole confinement layer and a potential for electrons (electron potential) is low in said electron confinement layer;
- said hole potential and said electron potential are lower in said quantum well layer than in said hole confinement layer and said electron confinement layer;
- said hole potential is higher in said hole barrier layer than in said hole confinement layer;
- and
- said electron potential is higher in said electron barrier layer than in said electron confinement layer;
- and
- wherein said p-cladding layer and said n-cladding layer have refractive indices smaller than at least one of refractive indices of said hole confinement layer and said electron confinement layer.
Dependencies are inferred from the claim text.