Light emitting element and method of making same
A light emitting element has a substrate of gallium oxides and a pn-junction formed on the substrate. The substrate is of gallium oxides represented by: (Al X In Y Ga (1−X−Y) ) 2 O 3 where 0≦x≦1, 0≦y≦1 and 0≦x+y≦1. The pn-junction has first conductivity type substrate, and GaN system compound semiconductor thin film of second conductivity type opposite to the first conductivity type.
1. A light emitting element, comprising;
a Ga 2 O 3 single crystal substrate;
a pn-junction formed on the substrate, the pn-junction including a first GaN system compound semiconductor thin film of first conductivity type formed on the substrate of the first conductivity type, and a second GaN system compound semiconductor thin film of second conductivity type opposite to the first conductivity type, the second GaN system compound semiconductor thin film being formed on the first GaN system compound semiconductor thin film.
2. The light emitting element according to claim 1 , wherein:
the first GaN system compound semiconductor thin film includes a third GaN system compound semiconductor thin film with a first predetermined bandgap energy, and a fourth GaN system compound semiconductor thin film with a second predetermined bandgap energy smaller than the first predetermined bandgap energy, the fourth GaN system compound semiconductor thin film being formed on the third GaN system compound semiconductor thin film; and the second GaN system compound semiconductor thin film has a third predetermined bandgap energy greater than the second predetermined bandgap energy.
3. The light emitting diode according to claim 2 , wherein: the third GaN system compound semiconductor thin film is selected from the group consisting of:
In a Ga 1−a N, GaN and Al b Ga 1−b N, where 0<a<1 and 0<b<1;
the fourth GaN system compound semiconductor thin film is of In c Ga 1−c N, where 0<c<1 and a<c; and
the second GaN system compound semiconductor thin film is of one material selected from GaN and Al d Ga 1−d N, where 0<d<1.
4. The light emitting diode according to claim 1 , wherein:
the substrate has a main plane of (101) face; and
the pn-junction is formed on the (101) face.
5. The light emitting diode according to claim 1 , wherein:
the first and second GaN system compound semiconductor thin films include V group elements an atom arrangement of which is nearly identical to that of oxygen atoms included in the substrate.