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US 8,299,497 B1Granted
Near-infrared photodetector with reduced dark current
AssigneeSandia Corporation
InventorsJohn F. Klem, Jin K. Kim
Life of this patent
Estimating the term…
Abstract
A photodetector is disclosed for the detection of near-infrared light with a wavelength in the range of about 0.9-1.7 microns. The photodetector, which can be formed as either an nBp device or a pBn device on an InP substrate, includes an InGaAs light-absorbing layer, an InAlGaAs graded layer, an InAlAs or InP barrier layer, and an InGaAs contact layer. The photodetector can detect near-infrared light with or without the use of an applied reverse-bias voltage and is useful as an individual photodetector, or to form a focal plane array.
Claims23
A photodetector, comprising:
- an indium phosphide (InP) substrate;
- a plurality of III-V compound semiconductor layers epitaxially grown on the InP substrate including:
- a light-absorbing layer comprising indium gallium arsenide (InGaAs) located above the InP substrate;
- an indium aluminum gallium arsenide (InAlGaAs) graded layer located above the light-absorbing layer;
- a barrier layer comprising indium aluminum arsenide (InAlAs) or InP located above the InAlGaAs graded layer, with the barrier layer having an energy level which is different from the energy level of the light-absorbing layer;
- and
- a contact layer comprising InGaAs located above the barrier layer;
- a first electrode electrically connected to the light-absorbing layer;
- and
- a second electrode electrically connected the contact layer.
7 more elements
A photodetector, comprising:
- an indium phosphide (InP) substrate;
- a plurality of III-V compound semiconductor layers epitaxially grown on the InP substrate including:
- a light-absorbing layer comprising indium gallium arsenide (InGaAs) located above the InP substrate, with the InGaAs being n-type doped;
- an indium aluminum gallium arsenide (InAlGaAs) graded layer located above the light-absorbing layer;
- a barrier layer comprising indium aluminum arsenide (InAlAs) located above the InAlGaAs graded layer, with the barrier layer having a valence band energy level which is different from the valence band energy level of the light-absorbing layer;
- and
- a contact layer comprising InGaAs located above the barrier layer, with the InGaAs being p-type doped;
- a first electrode electrically connected to the light-absorbing layer;
- and
- a second electrode electrically connected to the contact layer.
7 more elements
A photodetector, comprising:
- an indium phosphide (InP) substrate;
- a plurality of III-V compound semiconductor layers epitaxially grown on the InP substrate including:
- a light-absorbing layer comprising indium gallium arsenide (InGaAs) located above the InP substrate, with the InGaAs being p-type doped;
- a indium aluminum gallium arsenide (InAlGaAs) graded layer located above the light-absorbing layer;
- a barrier layer comprising indium aluminum arsenide (InAlAs) located above the InAlGaAs graded layer, with the barrier layer having a conduction band energy level which is different from the conduction band energy level of the light-absorbing layer;
- and
- a contact layer comprising InGaAs located above the barrier layer, with the InGaAs being n-type doped;
- a first electrode electrically connected to the light-absorbing layer;
- and
- a second electrode electrically connected to the contact layer.
7 more elements
A photodetector, comprising:
- an indium phosphide (InP) substrate;
- a plurality of III-V compound semiconductor layers epitaxially grown on the InP substrate including:
- a light-absorbing layer comprising indium gallium arsenide (InGaAs) located above the InP substrate, with the InGaAs being p-type doped;
- an indium aluminum gallium arsenide (InAlGaAs) graded layer located above the light-absorbing layer;
- a barrier layer comprising InP located above the InAlGaAs graded layer, with the InP barrier layer having a conduction band energy level which is different from the conduction band energy level of the light-absorbing layer;
- and
- a contact layer comprising InGaAs located above the barrier layer, with the InGaAs being n-type doped;
- a first electrode electrically connected to the light-absorbing layer;
- and
- a second electrode electrically connected to the contact layer.
7 more elements
Dependencies are inferred from the claim text.