| 摘要 |
PURPOSE:To prevent the characteristics from deteriorating due to the running of carriers in the impurity-doped semiconductor, by providing with non-doped semiconductor having a small energy gap between the P-N junction. CONSTITUTION:In a case where non-doped GaAs 30 is put between P-doped Al0.5Ga0.5As 29 and N-doped Al0.5Ga0.5As 31, two-dimensional hole gas 40 is produced on the hetero interface between the GaAs 30 and the P<-> Al0.5Ga0.5As 29, and two-dimensional electron gas 39 on the hetero interface between the GaAs 30 and the N<-> Al0.5Ga0.5As. In the non-doped GaAs 42, the potential gradient is created, and thus extremely large internal electrical field may be generated. Accordingly, when electrons 37 and holes 38 are created by light irradiation 44 in the non-doped GaAs layer 42, each carrier flows into the hetero interfaces at an almost saturated speed by the large internal electrical field. |
