| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a vehicular headlamp using a light emitting device easy to be manufactured because it has a simple structure and capable of stably providing high emission efficiency over a long period of time. <P>SOLUTION: This vehicular headlamp is provided with a light source including one or a plurality of light emitting devices (LEDs), and base members (a mount and a rear casing) for fixing the light source to the vehicle. The LED comprises: a GaN substrate 1; an n-type Al<SB>x</SB>Ga<SB>1-x</SB>N layer 3 on the side of the first principal surface of the GaN substrate 1; a P-type Al<SB>x</SB>Ga<SB>1-x</SB>N layer 5 positioned far from the n-type Al<SB>x</SB>Ga<SB>1-x</SB>N layer 3 when viewed from the GaN substrate 1; and a quantum well 4 positioned between the n-type Al<SB>x</SB>Ga<SB>1-x</SB>N layer 3 and the P-type Al<SB>x</SB>Ga<SB>1-x</SB>N layer 5. In the LED, the specific resistance of the GaN substrate 1 is 0.5 Ωcm or less, the side of the P-type Al<SB>x</SB>Ga<SB>1-x</SB>N layer 5 is down-mounted, and light is emitted from a second principal surface 1a opposite to the first principal surface of the GaN substrate 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
