Infrared photodetector with reticulated contact
AssigneeHRL Laboratories, LLC
InventorsHasan Sharifi, Terence J. De Lyon, Rajesh D. Rajavel
Life of this patent
Estimating the term…
Abstract
Using a highly doped Cap layer of the same composition as the Contact material in an nBn or pBp infrared photodetector allows engineering of the energy band diagram to facilitate minority carrier current flow in the contact region and block minority current flow outside the Contact region. The heavily doped Cap layer is disposed on the Barrier between the Contacts but electrically isolated from the Contact material.
Claims18
A photodetector with a reduced dark current, comprising:
- an absorber layer of a first area and comprising a first semiconductor;
- a barrier layer of the first area and comprising a second semiconductor disposed on the absorber layer;
- a contact layer with a second area and comprising a third semiconductor disposed on the barrier layer;
- and
- a cap layer comprising the third semiconductor disposed on the barrier layer with an area approximately equal to the first area less the second area,
- wherein the contact layer is electrically isolated from the cap layer by a dielectric;
- wherein the barrier layer comprises a first sublayer, a second sublayer, and a third sublayer;
- wherein the first sublayer substantially comprises Al0.3In0.7As0.7Sb0.3 and is disposed on the absorber layer;
- wherein the second sublayer is disposed on the first sublayer;
- wherein the third sublayer substantially comprises Al0.7In0.3As0.4Sb0.6 and is disposed on the second sublayer.
A photodetector with a reduced dark current, comprising:
- an absorber layer comprising a first semiconductor;
- a barrier layer comprising a second semiconductor disposed on the absorber layer,
- a contact layer comprising a third semiconductor disposed on a region of the barrier layer;
- and
- a cap layer comprising the third semiconductor disposed on the barrier layer wherein the contact layer is spaced apart from the cap layer by one hundred nanometers to three microns;
- wherein the contact layer is electrically isolated from the cap layer by a dielectric;
- wherein the barrier layer comprises a first sublayer, a second sublayer, and a third sublayer;
- wherein the first sublayer substantially comprises Al0.3In0.7As0.7Sb0.3 and is disposed on the absorber layer;
- wherein the second sublayer is disposed on the first sublayer;
- wherein the third sublayer substantially comprises Al0.7In0.3As0.4Sb0.6 and is disposed on the second sublayer.
A photodetector with a reduced dark current comprising a plurality of pixels wherein each pixel comprises:
- an absorber layer comprising a first semiconductor;
- a barrier layer comprising a second semiconductor disposed on the absorber layer;
- a contact layer comprising a third semiconductor disposed on a region of the barrier layer;
- and
- a cap layer comprising the third semiconductor disposed on the barrier layer;
- wherein the contact layer and the cap layer are reticulated by gaps between one to three microns;
- wherein the contact layer is electrically isolated from the cap layer by a dielectric;
- wherein the barrier layer comprises a first sublayer, a second sublayer, and a third sublayer;
- wherein the first sublayer substantially comprises Al0.3In0.7As0.7Sb0.3 and is disposed on the absorber layer;
- wherein the second sublayer is disposed on the first sublayer;
- wherein the third sublayer substantially comprises Al0.7In0.3As0.4Sb0.6 and is disposed on the second sublayer.
Dependencies are inferred from the claim text.