Stephen E Forrest

US Patent:

20040209116, Oct 21, 2004

Filed:

Oct 6, 2003

Appl. No.:

10/680066

Inventors:

Xiaofan Ren - Los Angeles CA, US
Russell Holmes - Princeton NJ, US
Stephen Forrest - Princeton NJ, US
Mark Thompson - Anaheim CA, US

International Classification:

H05B033/14

US Classification:

428/690000, 428/917000, 313/504000, 313/506000, 257/040000

Abstract:

The present invention relates to organic light emitting devices (OLEDs), and more specifically to efficient OLEDs having an emissive layer having host material with a wide energy gap. The present invention also relates to materials for use as a wide gap host material.

US Patent:

51723859, Dec 15, 1992

Filed:

Mar 5, 1991

Appl. No.:

7/665429

Inventors:

Stephen R. Forrest - Torrance CA
Franky F. So - Torrance CA
De Y. Zang - Irvine CA

Assignee:

University of Southern California - Los Angeles CA

International Classification:

H01S 319
G02B 610

US Classification:

372 50

Abstract:

Certain crystalline organic semiconductor compounds, such as 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA), when deposited by an ultrahigh vacuum process of organic molecular beam deposition, form highly ordered "quasi-epitaxial" films (32). Due to asymmetries in the molecular crystal structure of such compounds, the ordering of the films results in giant asymmetries in their dielectric properties. Such large dielectric asymmetries permit the construction of a variety of devices, including optical isolators (38), optically isolated lasers (48), optical isolated optical amplifiers (64), polarization-selective photodiodes (76), and metal-organic-inorganic semiconductor-metal detectors, among others.

US Patent:

48762091, Oct 24, 1989

Filed:

May 12, 1989

Appl. No.:

7/351063

Inventors:

Stephen R. Forrest - Torrance CA

Assignee:

U.S.C. - Los Angeles CA

International Classification:

H01L 2176

US Classification:

437 5

Abstract:

The disclosed invention as directed to a semiconductor material avalanche photodiode of a separate multiplication and absorption region heterostructure design (SAM-APD). The improved SAM-APD of this invention is characterized by a plurality of floating guard rings which are separated about a central region and doped in the opposite high concentration from that of the multiplication region in which they are positioned. These rings float in the sense that they have no contact with the metalized p-contact of the photodiode; and, therefore, no direct contact with the current source. This structure results in an enhanced avalanche effect in the central region with limited edge breakdown undesirable consequences. In addition to this structure, an alternative embodiment suggest the use of both a floating ring and thin slab below the central region, of a dimension slightly smaller than the smaller region and concentric with it to achieve an optimized central avalanche breakdown with reducd edge breakdown of the electric fields formed during reversed biasing of the APD (avalanche photodiode).

US Patent:

50724398, Dec 10, 1991

Filed:

Mar 16, 1990

Appl. No.:

7/494640

Inventors:

Stephen R. Forrest - Torrance CA
Gregory L. Tangonan - Oxnard CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H04J 1400

US Classification:

359115

Abstract:

A high speed opto-electronic crossbar switch 10 disposed to selectively connect signals carried by first and second input optical beams to an output node 42. The inventive switch 10 includes a selectively actuatable photodetector network 22 for converting the signals carried by the first and second input beams to electrical output signals, and for impressing these output signals upon the output node 42. The photodetector network 22 has a first photodetector 30 in optical alignment with the first input beam, and a second photodetector 32 in optical alignment with the second input beam. The inventive crossbar switch 10 further includes a multiplexer 26 for actuating the first and second photodetectors 30, 32 in response to a control signal. The invention also includes a laser diode circuit 24 for illuminating the first and second photodetectors 30, 32 in response to the control signal.

US Patent:

53151291, May 24, 1994

Filed:

May 1, 1991

Appl. No.:

7/694108

Inventors:

Stephen R. Forrest - Torrance CA
Franky F. So - Torrance CA

Assignee:

University of Southern California - Los Angeles CA

International Classification:

H01L 2928

US Classification:

257 21

Abstract:

Organic optoelectronic devices, such as a modulator (54) and a photodetector (73) comprising alternating layers (58) of two crystalline planar organic aromatic semiconductors (60 and 62), have been grown by organic molecular beam deposition. These organic substances have been deposited in ultra-thin layers only 10. ANG. in depth using organic molecular beam deposition methods. Due to the anisotropic character of these organic materials,, the devices formed using these methods possess unique electronic and optical properties. The preferred embodiment of the invention utilizes 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) and 3,4,7,8-naphthalenetetracarboxylic dianhydride (NTCDA). While the inventors have identified PTCDA and NTCDA as excellent materials for the manufacture of organic optoelectronic IC devices, the broad scope of the present invention encompasses the use of any planar organic aromatic semiconductor which readily forms a crystalline structure. The preferred method of the invention employs a chamber (23) containing an inorganic substrate (32) with appropriate material for making electrical contact to the organic structures and sources of PTCDA (36) and NTCDA (38).

US Patent:

48579823, Aug 15, 1989

Filed:

Jan 6, 1988

Appl. No.:

7/141320

Inventors:

Stephen R. Forrest - Torrance CA

Assignee:

University of Southern California - Los Angeles CA

International Classification:

H01L 2714

US Classification:

357 30

Abstract:

The disclosed invention as direction to a semiconductor material avalanche photodiode of a separate multiplication and absorption region heterostructure design (SAM-APD). The improved SAM-APD of this invention is characterized by a plurality of floating guard rings which are separated about a central region and doped in the opposite high concentration from that of the multiplication region in which they are positioned. These rings float in the sense that they have no contact with the metalized p-contact of the photodiode; and, therefore, no direct contact with the current source. This structure results in an enhanced avalanche effect in the central region with limited edge breakdown undesirable consequences. In addition to this structure, an alternative embodiment suggests the use of both a floating ring and this slab below the central region, of a dimension slightly smaller than the smaller region and concentric with it to achieve an optimized central avalanche breakdown with reduced edge breakdown of the electric fields formed during reversed biasing of the APD (avalanche photodiode).

US Patent:

20190237694, Aug 1, 2019

Filed:

Jan 30, 2019

Appl. No.:

16/262408

Inventors:

- Los Angeles CA, US
- Ann Arbor MI, US
Muazzam IDRIS - Los Angeles CA, US
Karim EL ROZ - Los Angeles CA, US
Daniel Sylvinson MUTHIAH RAVINSON - Los Angeles CA, US
Stephen R. FORREST - Ann Arbor MI, US
Chan Ho SOH - Ann Arbor MI, US

International Classification:

H01L 51/50
H01L 51/00
C07D 233/58
C07D 401/10
C09K 11/06

Abstract:

A hybrid emissive layer and OLED incorporating the same are provided. The hybrid emissive layer includes a first material having a triplet state energy level T1and a singlet state energy level S1, a second material having a triplet state energy level T1and a singlet state energy level S1; and a third material having a triplet state energy level T1and a single state energy level S1, where T1≥T1; S1≤S1; and T1