| 摘要 |
PURPOSE:To increase the light output from the light-take-out surface, by providing fine and irregular indentations on the light-take-out surface of an N-type Ga1-x AlxAs layer and thereby reducing the total reflection taking place at the boundary of air and the light-take-up surface. CONSTITUTION:In this photodiode, N-type Ga1-xAlxAs layer 3, N-type Ga1-y AlyAs layer 11 and P-type GaAs layer 6 are formed by epitaxial growth on N-type GaAs base 2, a window reaching N-type Ga1-xAlxAs layer 3 is provided on a part of N-type CaAs base 2, and the surface on N-type Ga1-xAlxAs layer 3 is made rough. The junction between P-type region 13 diffused from P-type CaAs layer 6 and N-type Ga1-xAlxAs layer 3 forms light-emission region 9. Since N-type Ga1-y AlyAs layer 11 has a larger band gap than N-type Ga1-xAlxAs layer 12, current does not flow in the junction with P-type region 13 but concentrates and flows in the junction between P-type region 13 and the Ga1-xAlxAs layer. |
