Quantum dots, nanocomposite materials with quantum dots, devices with quantum dots, and related fabrication methods

• US 7,005,669 B1
• Filed: 08/02/2002
• Issued: 02/28/2006
• Est. Priority Date: 08/02/2001
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: UltraDots, Inc. (Omnipv Incorporated)
• Inventors: Lee, Howard Wing Hoon
• Primary Examiner(s): JACKSON JR, JEROME
• Application Number:
  US10/212,002
• Time in Patent Office: 1,306 Days
• Field of Search: 257/14, 257/17, 257/21, 359/248
• US Class Current: 257/21
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 6/02195 characterised by means for tuning the grating
• CPC Class Codes: G02B 6/12011 characterised by the arrayed waveguides, e.g. comprising a filled groove in the array section
• CPC Class Codes: G02F 1/01791 Quantum boxes or quantum dots
• CPC Class Codes: G02F 1/3517 using an interferometer
• CPC Class Codes: G02F 1/3556 Semiconductor materials, e.g. quantum wells
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials
• CPC Class Codes: G02F 3/00 Optical logic elements; Optical bistable devices
• CPC Class Codes: Y10S 977/834 Optical properties of nanomaterial, e.g. specified transparency, opacity, or index of refraction

Abstract

The invention provides “engineered” nonlinear nanocomposite materials with an extremely large χ⁽³⁾ and fast temporal response along with optical properties that can be precisely tuned to satisfy the requirements of a particular application (e.g., optical, thermal, mechanical, etc.). In particular, the magnitude of the linear and nonlinear index of refraction can be adjusted substantially independently of the absorption spectrum of the material. In addition, the optical characteristics can be engineered substantially independently from the mechanical and chemical characteristics, providing exceptional performance and flexibility in terms of device-incorporation and process-stability.

Claims

1. An engineered nonlinear nanocomposite material comprising:

a matrix material; and

a semiconductor quantum dot comprising a shell,

the nanocomposite material having a nonlinear index of refraction that is greater than 10<sup>−

9</sup> cm²/W.

2. The nanocomposite material of claim 1, wherein the semiconductor quantum dot is a silicon quantum dot.

3. The nanocomposite material of claim 1, wherein the semiconductor quantum dot is a germanium quantum dot.

4. The nanocomposite material of claim 1, wherein the shell is SiO_x where x is selected between the range of 0 to 2.

5. The nanocomposite material of claim 1, wherein the shell is GeO_x where x is selected between the range of 0 to 2.

6. The nanocomposite material of claim 1, wherein the semiconductor quantum dot further comprises a substantially defect free silicon crystal core with a maximum dimension between 1 and 10 nm, and the shell is a substantially noncrystalline silicon-oxide shell surrounding the silicon crystal core, with a maximum dimensional width between 0.1 nm and 5 nm, such that the average molecular formula of the silicon-oxide shell is characterized by SiO_r, with r between 0 and 2.

7. The nanocomposite material of claim 6, wherein the semiconductor quantum dot further comprises a set of comprising one or more different organic molecules R(R) bound to the outer surface of the silicon-oxide shell such that the average surface density of R ranges from 0 to 4 molecules per nm² across the outer surface of the silicon-oxide shell.

8. The nanocomposite material of claim 1, wherein the semiconductor quantum dot further comprises a substantially defect free germanium crystal core with a maximum dimension between 1 and 10 nm, and the shell is a substantially noncrystalline germanium-oxide shell surrounding the germanium crystal core, with a maximum dimensional width between 0.1 nm and 5 nm, such that the average molecular formula of the germanium-oxide shell is characterized by GeO_r, with r between 0 and 2.

9. The nanocomposite material of claim 8, wherein the semiconductor quantum dot further comprises a set of organic molecules R bound to the outer surface of the germanium-oxide shell, and imparts nonlinearity.