Epir Technologies, Inc.

Sivananthan Laboratories, Inc.

Christoph H Grein

Sivalingam Sivananthan

Silviu Velicu

Anthony Joseph Ciani

Richard Edward Pimpinella

James K Garland

Christopher Frank Buurma

Paul Boieriu

Sir B Rafol

Jered Feldman

Wayne H Lau

A process for the post-deposition treatment of colloidal quantum dot films to improve photodetector performance. A colloidal quantum dot film is first deposited on a suitable substrate or device structure, given a ligand exchange, and then allowed to dry into a completed film. Next, a solution is prepared consisting of dilute HOmixed with a polar solvent such as isopropyl alcohol solution. The prepared film and substrate are then immersed into the prepared solution over a set interval of time. After which, the film is removed and rinsed with solvent, then dried with clean Ngas. After this treatment, the colloidal quantum dot film is ready for use as a photodetector.

Process for the post-deposition treament of colloidal quantum dot photodetector films to improve performance by using hydrogen peroxide

A photodetector device is provided that includes a ROIC having a top surface with a plurality of electrically conductive first electrodes within a pattern of surface areas on the top surface each surface area having a border, and an electrically conductive electrode grid having a portion on the border of each of the surface areas; and a photodetector film overlying the surface area. The electrode grid can be configured to surround each surface area to define the borders of the surface areas as pixels. The photodetector film can be a colloidal quantum dot film. The ROIC has circuit elements signal-connected to the plurality of first electrodes. Methods for forming the photodetector device include photolithography and deposition methods.

Adjacent electrode which provides pixel delineation for monolithic integration of a colloidal quantum dot photodetector film with a readout integrated circuit

A process and apparatus is provided to generate and introduce hydrogen from an inductively coupled plasma system into a type II superlattice wafer. The type II superlattice wafer can contain a number of detectors formed on one of its faces. The process can use hydrogen plasma with a total chamber pressure of 20-300 mTorr, a hydrogen gas flow of 50-100 sccm, an ICP power of 100-900 W, a secondary RF power of 15-90 W, and a process duration adjusted to maximize the benefit of hydrogenation (typically between several tens and several hundreds of seconds). The process can introduce a secondary gas to facilitate the plasma ignition, hydrogen ionization and recombination processes or hydrogen diffusion and impingement onto the type II superlattice wafer.

Inductively coupled plasma for hydrogenation of type II superlattices

A Group II-VI photovoltaic solar cell comprising at least two and as many as five subcells stacked upon one another. Each subcell has an emitter layer and a base layer, with the base of the first subcell being made of silicon, germanium, or silicon-germanium. The remaining subcells are stacked on top of the first subcell and are ordered such that the band gap gets progressively smaller with each successive subcell. Moreover, the thicknesses of each subcell are optimized so that the current from each subcell is substantially equal to the other subcells in the stack. Examples of suitable Group II-VI semiconductors include CdTe, CdSe, CdSeTe, CdZnTe, CdMgTe, and CdHgTe.

High efficiency multijunction II-VI photovoltaic solar cells

A method of forming a diode comprises the steps of forming an extraction region of a first conductivity type, forming an active region of a second conductivity type that is opposite the first conductivity type, and forming an exclusion region of the second conductivity type to be adjacent the active region. The active region is formed to be adjacent to the extraction region and along a reverse bias path of the extraction region and the exclusion region does not resupply minority carriers while removing majority carriers. At least one of the steps of forming the exclusion region and forming the extraction region includes the additional step of forming a barrier that substantially reduces the flow of the carriers that flow toward the active region, but does not rely on a diffusion length of the carriers to block the carriers.

Method for creating nonequilibrium photodetectors with single carrier species barriers

A photosensitive diode has an active region defining a majority carrier of a first conductivity type and a minority carrier of a second conductivity type. An extraction region is disposed on a first side of the active region and extracts minority carriers from the active region. It also has majority carriers within the extraction region flowing toward the active region in a condition of reverse bias. An exclusion region is disposed on a second side of the active region and has minority carriers within the exclusion region flowing toward the active region. It receives majority carriers from the active region. At least one of the extraction and exclusion region provides a barrier for substantially reducing flow of one of the majority carriers or the minority carriers, whichever is flowing toward the active region, while permitting flow of the other minority carriers or majority carriers flowing out of the active region. The barrier substantially reduces flow of the carriers without relying on diffusion length of the one carriers in order to reduce the flow.

Nonequilibrium photodetectors with single carrier species barriers

A detector of incident infrared radiation has a first region with a first spectral response, and a second region with a second, different spectral response. The second absorption region is stacked on the first and may be separated therefrom by a region in which the chemical composition of the compound semiconductor is graded. Separate contacts are provided to the first and second absorption regions and a further common contact is provided so as to permit the application of either a bias voltage or a skimming voltage across the respective pn junctions. The detector may be operated such that a preselected one of the absorption regions responds to incident infrared radiation of a predetermined waveband while the other absorption region acts as a skimmer of dark current, thereby enhancing the signal to noise ratio of the detector.

Photodetector with dark current reduction

A photosensitive diode has superlattice exclusion region formed from a stack of first and second layers. The first layers are penetrated by minority carriers using quantum mechanical tunneling and reduce minority carrier mobility. The second layers have a sufficiently low bandgap that the tunneling minority carriers can reach an active region of the diode. The process of successively forming first and second layers is repeated until the exclusion region is at least three times the minority carrier diffusion length.

Forming a photodiode to include a superlattice exclusion layer

A photosensitive diode has an active region defining a majority carrier of a first conductivity type and a minority carrier of a second conductivity type. At least one extraction region is disposed on a first side of the active region and has a majority carrier of the second conductivity type. Carriers of the second conductivity type are extracted from the active region and into the extraction region under a condition of reverse bias. At least one exclusion region is disposed on a second side of the active region and has a majority carrier of the first conductivity type. The exclusion region prevents entry of its minority carriers, which are of the second conductivity type, into the active region while in a condition of reverse bias. The exclusion region includes a superlattice with a plurality of layers.

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Wheaton, IL, United States of America

Christoph H Grein