Patents by Inventor Stephen Forrest

Stephen Forrest has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7242703
    Abstract: An unipolar organic injection laser in which electrically-stimulated intraband transitions result in lasing. An active region includes at least one organic injector layer and at least one organic emitter layer. Each organic emitter layer has a first energy level and a second energy level on a same side of an energy gap defined by a conduction band and a valance band. Charge carriers are injected through the organic injector layer into the first energy level of the organic emitter layer when a voltage is applied across active region. The difference in energy between the first and second energy levels produces radiative emissions when charge carriers transition from the first energy level to the second energy level. Population inversion is maintained between the first and second energy levels, producing stimulated emission and lasing.
    Type: Grant
    Filed: December 21, 2004
    Date of Patent: July 10, 2007
    Assignee: The Trustees of Princeton University
    Inventors: Stephen Forrest, Vinod Menon, Zoltan Soos
  • Publication number: 20070137693
    Abstract: A plurality of quantum dots comprise a first inorganic material, and each quantum dot is coated with a second inorganic material. The coated quantum dots being are in a matrix of a third inorganic material. At least the first and third materials are photoconductive semiconductors. The second material is arranged as a tunneling barrier to require a charge carrier (an electron or a hole) at a base of the tunneling barrier in the third material to perform quantum mechanical tunneling to reach the first material within a respective quantum dot. A first quantum state in each quantum dot is between a conduction band edge and a valence band edge of the third material in which the coated quantum dots are embedded. Wave functions of the first quantum state of the plurality of quantum dots may overlap to form an intermediate band.
    Type: Application
    Filed: December 16, 2005
    Publication date: June 21, 2007
    Inventor: Stephen Forrest
  • Publication number: 20070131172
    Abstract: Methods for preparing organic thin films on substrates, the method comprising the steps of providing a plurality of organic precursors in the vapor phase, and reacting the plurality or organic precursors at a sub-atmospheric pressure. Also included are thin films made by such a method and apparatuses used to conduct such a method. The method is well-suited to the formation of organic light emitting devices and other display-related technologies.
    Type: Application
    Filed: January 19, 2007
    Publication date: June 14, 2007
    Inventors: Stephen Forrest, Paul Burrows, Vladimir Ban
  • Publication number: 20070132369
    Abstract: A multicolor organic light emitting device employs vertically stacked layers of double heterostructure devices which are fabricated from organic compounds. The vertical stacked structure is formed on a glass base having a transparent coating of ITO or similar metal to provide a substrate. Deposited on the substrate is the vertical stacked arrangement of three double heterostructure devices, each fabricated from a suitable organic material. Stacking is implemented such that the double heterostructure with the longest wavelength is on the top of the stack. This constitutes the device emitting red light on the top with the device having the shortest wavelength, namely, the device emitting blue light, on the bottom of the stack. Located between the red and blue device structures is the green device structure.
    Type: Application
    Filed: February 2, 2007
    Publication date: June 14, 2007
    Inventors: Stephen Forrest, Mark Thompson, Paul Burrows, Vladimir Bulovic, Gong Gu
  • Publication number: 20070116983
    Abstract: The present invention relates to phosphorescent stacked OLEDs having an interlayer.
    Type: Application
    Filed: November 23, 2005
    Publication date: May 24, 2007
    Inventors: Hiroshi Kanno, Stephen Forrest
  • Publication number: 20070110357
    Abstract: An asymmetric twin waveguide (ATG) structure with an integrated amplifier and detector fabricated in a single active waveguide layer is disclosed. The structure comprises an active waveguide layer formed on a passive waveguide layer. The active and passive waveguides have different effective indices of refraction such that a first mode of light is confined primarily to the active waveguide and a second mode of light is confined primarily to the passive waveguide in the area where the waveguides overlap.
    Type: Application
    Filed: November 15, 2005
    Publication date: May 17, 2007
    Inventors: Stephen Forrest, Kuen-Ting Shiu, Shashank Agashe
  • Publication number: 20070108890
    Abstract: The present invention is directed to a an organic imaging device having organic detectors on a curved surface. The device may be used for imaging applications such as photography, lightweight camera systems, very high-resolution imaging, lightweight “night vision”, robotic vision, and others. A concave housing with a deformable lens is provided. The deformable lens allows for a range of fields of view and focal lengths. The invention may be configured to detect a range of electromagnetic radiation. It may then provide input to a computer, display, or other device for processing or display of the detected radiation as an image.
    Type: Application
    Filed: November 15, 2005
    Publication date: May 17, 2007
    Inventor: Stephen Forrest
  • Publication number: 20070096085
    Abstract: A photosensitive device includes a series of organic photoactive layers disposed between two electrodes. Each layer in the series is in direct contact with a next layer in the series. The series is arranged to form at least one donor-acceptor heterojunction, and includes a first organic photoactive layer comprising a first host material serving as a donor, a thin second organic photoactive layer comprising a second host material disposed between the first and a third organic photoactive layer, and the third organic photoactive layer comprising a third host material serving as an acceptor. The first, second, and third host materials are different. The thin second layer serves as an acceptor relative to the first layer or as a donor relative to the third layer.
    Type: Application
    Filed: November 2, 2005
    Publication date: May 3, 2007
    Inventors: Barry Rand, Stephen Forrest
  • Publication number: 20070087449
    Abstract: A method of purifying small molecule organic material, performed as a series of operations beginning with a first sample of the organic small molecule material. The first step is to purify the organic small molecule material by thermal gradient sublimation. The second step is to test the purity of at least one sample from the purified organic small molecule material by spectroscopy. The third step is to repeat the first through third steps on the purified small molecule material if the spectroscopic testing reveals any peaks exceeding a threshold percentage of a magnitude of a characteristic peak of a target organic small molecule. The steps are performed at least twice. The threshold percentage is at most 10%. Preferably the threshold percentage is 5% and more preferably 2%. The threshold percentage may be selected based on the spectra of past samples that achieved target performance characteristics in finished devices.
    Type: Application
    Filed: September 29, 2006
    Publication date: April 19, 2007
    Inventors: Rhonda Salzman, Stephen Forrest
  • Publication number: 20070077017
    Abstract: An asymmetric twin waveguide (ATG) structure with quantum-well intermixing in the taper region of the active waveguide is disclosed. The structure comprises a first waveguide, a second waveguide, and a taper formed in the second waveguide. The taper has an intermixed area formed therein comprising a plurality of quantum wells intermixed with a plurality of barriers. The quantum wells and barriers may be intermixed using plasma-enhanced intermixing such as, for example, Argon plasma enhanced intermixing. Quantum-well intermixing reduces absorption loss normally encountered in the movement of light between waveguides.
    Type: Application
    Filed: September 30, 2005
    Publication date: April 5, 2007
    Applicant: The Trustees of Princeton University
    Inventors: Vinod Menon, Milind Gokhale, Stephen Forrest, Yu Huang, Fengnian Xia
  • Patent number: 7196835
    Abstract: A structure is provided that includes an aperiodic dielectric stack. The structure may include a substrate, a device disposed over the substrate, and a first dielectric stack disposed between the substrate and the device. The first dielectric stack includes a plurality of layers comprising a first dielectric material, wherein at least two of the layers comprising a first dielectric material have substantially different thicknesses, as well as a plurality of layers comprising a second dielectric material. The average outcoupling efficiency into air of the device over a bandwidth of at least 300 nm may be at least 40% greater than that of an otherwise identical device disposed in a structure without the first dielectric stack.
    Type: Grant
    Filed: June 1, 2004
    Date of Patent: March 27, 2007
    Assignee: The Trustees of Princeton University
    Inventors: Peter Peumans, Stephen Forrest
  • Patent number: 7196366
    Abstract: A device is provided having a first electrode, a second electrode, a first photoactive region having a characteristic absorption wavelength ?1 and a second photoactive region having a characteristic absorption wavelength ?2. The photoactive regions are disposed between the first and second electrodes, and further positioned on the same side of a reflective layer, such that the first photoactive region is closer to the reflective layer than the second photoactive region. The materials comprising the photoactive regions may be selected such that ?1 is at least about 10% different from ?2. The device may further comprise an exciton blocking layer disposed adjacent to and in direct contact with the organic acceptor material of each photoactive region, wherein the LUMO of each exciton blocking layer other than that closest to the cathode is not more than about 0.3 eV greater than the LUMO of the acceptor material.
    Type: Grant
    Filed: August 5, 2004
    Date of Patent: March 27, 2007
    Assignee: The Trustees of Princeton University
    Inventors: Stephen Forrest, Jiangeng Xue, Soichi Uchida, Barry P. Rand
  • Publication number: 20070044836
    Abstract: A system comprising a plurality of organic photovoltaic cells arranged in a stack disposed between a first electrode and a second electrode, and a resistive load electrically connected across the first electrode and the second electrode. Each cell comprises a rectifying junction at an interface of organic semiconductor materials. There is metal or metal substitute disposed in the stack between each of the cells. At least a first cell and a second cell of the plurality of organic photovoltaic cells have different absorption characteristics. Photocurrent from the plurality of organic photovoltaic cells energizes the resistive load.
    Type: Application
    Filed: October 6, 2006
    Publication date: March 1, 2007
    Inventors: Stephen Forrest, Vladimir Bulovic
  • Publication number: 20070045661
    Abstract: An organic photosensitive optoelectronic device having a plurality of cells disposed between a first electrode and a second electrode. Each cell includes a photoconductive organic hole transport layer adjacent to a photoconductive organic electron transport layer. A metal or metal substitute is disposed between each of the cells. At least one exciton blocking layer is disposed between the first electrode and the second electrode.
    Type: Application
    Filed: February 9, 2006
    Publication date: March 1, 2007
    Inventors: Stephen Forrest, Vladimir Bulovic, Peter Peumans
  • Patent number: 7179534
    Abstract: A switch, used as an electronic-memory element, comprising a conductive organic polymer layer sandwiched between, and in contact with, two metallic conductive elements. In an initial post-fabrication state, the organic polymer layer is relatively highly conductive, the post-fabrication constituting a first stable state of the memory element that can serve to represent a binary bit “1 or 0,” depending which of two possible encoding conventions is employed. A relatively high voltage pulse can be passed between the two metal conductive elements, resulting in a market decrease in the current-carrying capacity of the organic polymer layer sandwiched between the two conductive elements. This change in conductivity of the organic polymer layer is generally irreversible, and constitutes a second stable state of the memory element that may be used to encode a binary bit “0” or “1,” again depending on which of two possible encoding conventions are employed.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: February 20, 2007
    Assignee: Princeton University
    Inventors: Stephen Forrest, Sven Moeller
  • Publication number: 20060286409
    Abstract: Organic light emitting devices are disclosed, which comprise a heterostructure for producing electroluminescence, wherein the heterostructure comprises an emissive layer containing a phosphorescent dopant compound.
    Type: Application
    Filed: August 23, 2006
    Publication date: December 21, 2006
    Inventors: Mark Thompson, Yujian You, Andrei Shoustikov, Scott Sibley, Paul Burrows, Stephen Forrest
  • Publication number: 20060279204
    Abstract: The present invention relates to OLEDs utilizing direct injection to the triplet state. The present invention also relates to OLEDs utilizing resonant injection and/or stepped energy levels.
    Type: Application
    Filed: November 16, 2005
    Publication date: December 14, 2006
    Inventors: Stephen Forrest, Julia Brown, Mark Thompson
  • Publication number: 20060279203
    Abstract: The present invention relates to organic light emitting devices (OLEDs), and more specifically to OLEDS that emit light using a combination of fluorescent emitters and phosphorescent emitters for the efficient utilization of all of the electrically generated excitons.
    Type: Application
    Filed: June 1, 2006
    Publication date: December 14, 2006
    Inventors: Stephen Forrest, Yiru Sun, Noel Giebink, Mark Thompson
  • Publication number: 20060278944
    Abstract: A photosensitive cell includes an anode and a cathode; a donor-type organic material and an acceptor-type organic material forming a donor-acceptor junction connected between the anode and the cathode; and an exciton blocking layer connected between the acceptor-type organic material of the donor-acceptor junction and the cathode, the blocking layer consisting essentially of a material that has a hole mobility of at least 10?7 cm2NV-sec or higher, where a HOMO of the blocking layer is higher than or equal to a HOMO of the acceptor-type material.
    Type: Application
    Filed: June 13, 2005
    Publication date: December 14, 2006
    Inventors: Barry Rand, Stephen Forrest, Mark Thompson
  • Publication number: 20060273714
    Abstract: The present invention relates to organic light emitting devices (OLEDs), and more specifically to OLEDS that emit light using a combination of fluorescent emitters and phosphorescent emitters for the efficient utilization of all of the electrically generated excitons.
    Type: Application
    Filed: June 1, 2005
    Publication date: December 7, 2006
    Inventors: Stephen Forrest, Yiru Sun, Noel Giebink, Mark Thompson