Avalanche photodiode with hetero-periodical structure
AssigneeNEC Corporation
InventorsMasayoshi Tsuji, Kikuo Makita
Life of this patent
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Abstract
An avalanche photodiode includes an avalanche multiplication layer of a hetero-periodical structure consisting of alternately provided barrier and well layers. Each barrier layer includes a multi-quantum barrier layer consisting of alternately provided short-width barrier and well layers. The barrier and well layers include respectively first and second III-group elements which meet the following conditions: E.sub.A <E.sub.B, and E.sub.A +E.sub.gA <E.sub.B +E.sub.gB or E.sub.A <E.sub.B, and E.sub.A +E.sub.gA >E.sub.B +E.sub.gB where E.sub.A and E.sub.B are average ionization energies of the first and second III-group elements respectively, and E.sub.gA and E.sub.gB are forbidden band gap energies, respectively.
Claims12
An avalanche photodiode, comprising:
- a light absorbing layer;
- an avalanche multiplication layer of a hetero-periodical structure comprising alternately provided first barrier and well layers, each of said first barrier layers of said avalanche multiplication layer comprising a multi-quantum barrier layer having alternately provided narrow-width barrier and well layers, a virtual barrier being formed which is higher than said first barrier and is generated at the multi-quantum barrier layer, so that electrons which are injected into the avalanche multiplication layer experience large energy differences between the virtual barrier and the well layer so that electrons obtain a large ionizing energy;
- and
- first and second electrodes for applying a predetermined voltage across said light absorbing and avalanche multiplication layers;
- wherein said narrow-width barrier and well layers comprise respectively first and second group III-V compounds which meet the following conditions:
- E.sub.A <E.sub.B, and E.sub.A +E.sub.gA <E.sub.B +E.sub.gB
- where E.sub.A and E.sub.B are average ionization energies of said first and second group III-V compounds, respectively, and E.sub.gA and E.sub.gB are forbidden band gap energies, respectively.
An avalanche photodiode, comprising:
- a light absorbing layer;
- an avalanche multiplication layer of a hetero-periodical structure consisting of alternately provided first barrier and well layers, each of said first barrier layers of said avalanche multiplication layer comprising a multi-quantum barrier layer consisting of alternately provided narrow-width barrier and well layers;
- and
- first and second electrodes for applying a predetermined voltage across said light absorbing and avalanche multiplication layers;
- wherein said first barrier and well layers comprise respectively first and second group III-V compounds which meet the following conditions:
- E.sub.A <E.sub.B, and E.sub.A +E.sub.gA >E.sub.B +E.sub.gB
- where E.sub.A and E.sub.B are average ionization energies of said first and second group III-V compounds, respectively, and E.sub.gA and E.sub.gB are forbidden band gap energies, respectively.
Dependencies are inferred from the claim text.