Semiconductor apparatus with band energy alignments

A semiconductor apparatus comprising:

• a first semiconductor layer of a first conductivity type;
• a second semiconductor layer of a second conductivity type;
• and
• a third semiconductor layer of the first conductivity type, wherein:
• the second semiconductor layer is formed between the first and third semiconductor layers, and the first and second semiconductor layers are in contact with each other;
• a first energy level at a bottom edge of a conduction band of the first semiconductor layer is lower than a second energy level at a top edge of a valence band of the second semiconductor layer;
• the second energy level is higher than a Fermi level in the second semiconductor layer;
• a third energy level at a bottom edge of a conduction band of the third semiconductor layer is higher than the Fermi level;
• the first semiconductor layer is formed of n+-In0.53Ga0.47As;
• and
• the second semiconductor layer is formed of p+-GaAs0.51Sb0.49.