Talk:Quantum dot

• Re: "Compare to quantum wires (confined in 2D) and quantum wells (confined in 1D)."... Is that right?? I'd think that wires correspond to 1D, and wells to 0D (a point)... --Cheese Sandwich 20:40, 19 August 2005 (UTC)
• You've misread/misunderstood the sentence. A wire is confined in two of its dimensions - thus it is a one dimensional structure. A well is confined in one dimension, and it is thus a two dimensional structure. A dot is effectively comfined in all three spatial dimensions, it is a zero dimensional structure. Daz - 9/11/06
• Also: This sentence portion could use some editing: "...as the larger and more red-shifted the Quantum Dots is, the less the quantum properties are." --Cheese Sandwich 20:43, 19 August 2005 (UTC)

Is there somewhere in the public domain one of those beautiful (and prevalent) pictures of solutions of quantum dots emitting at different wavelengths? If someone could find one, I think it would add to the appeal of this article. If not, perhaps some group would release their copyright for the exposure... To give an idea of what I'm talking about, here's a link http://www.research.philips.com/newscenter/pictures/downloads/ldm-nanotech_04-0_h.jpg to an awful enlargement of one of these displays. Jonnyapple 06:28, 2 February 2006 (UTC)

Company by this name

There is a company, Quantum Dot, that could be treated with an article; "Quantum Dot" currently redirects to "Quantum dot". The website is located at http://www.qdots.com . The company would fall into the Category:Research support companies. Courtland 23:38, 26 November 2005 (UTC)

The first company to offer commerical quantum dots was Evident Technologies in 2001. The company is currently located in Troy, New York; website: www.evidenttech.com. Commercial quantum dots include CdSe, PbS, and InGaP quantum dots for life science applications, LEDs, solar cells etc.

Images

This article needs some illustrations.--24.241.230.126 17:29, 31 March 2006 (UTC)

Good article nomination

Sadly, this article failed it's nomination. This is for two main reasons:

1. Past the lead (which while too short is understandable), it is unitelligible to a non-specialist (like myself).
2. It has no inline citations whatsoever.

Regards, --Celestianpower ^háblame 23:41, 12 April 2006 (UTC)

Move/redirect

I think this article should be moved to its more precise scientific name: semiconductor nanocrystal. --Sunpower 14:37, 26 April 2006 (UTC)

Big mistake!

I am pretty sure this sentence is wrong: "Quantum dots have quickly found their way into homes in many electronics. The new PlayStation 3 and high-definition DVD players (notably Blu-ray and HD-DVD) to come out all use a blue laser for data reading. The blue laser up until only a few years ago was beginning to be seen as something of an impossibility, until the synthesis of a blue quantum dot laser."

Blu-ray and HD-DVD use gallium nitride (and other nitrogen-base compounds) as materials for quantum wells structures, not quantum dots! Quantum dot lasers are just now trying to find their way into the market, but absolutely not in the short wavelength region (green-blue-violet)! Quantum dots have nothing to do with blue lasers!

I would recommend to correct such a sentence, or (better) to completely erase it off.

Please see blue laser and the reference in Appl. Phys. Lett. 86, 073102 (2005).

While the wikipedia entry says today: "Use of indium gallium nitride as a semiconductor material suitable for formation of quantum heterostructures is proposed. Recently, CdS/ZnS quantum dots have been used as the gain material in spherical Whispering Gallery Mode lasers; see Applied Physics Letters, 2005, 86:073102.", the reference does not mention the term quantum dots. Someone can give an opinion here? (Please sign your comments).

Miguel Andrade 18:29, 14 July 2006 (UTC)

• A quick note on the use of "quantum dot" vs "nanocrystal." In common usage the two terms are more or less interchangable. However, over the past several years, the nanoscience community has started to make a distinction between what each term refers to. Generally, "quantum dot" refers to small semiconductor islands grown onto a substrate using molecular beam epitaxy, chemical vapor deposition or other methods, and hence are fixed in place. In contrast, "nanocrystal" usually refers to colloidal particles grown in solution, which can then be processed using different methods. The APL article mentioned above uses colloidal CdS/ZnS particles which are then deposited onto substrates to make devices (rather than being grown there directly), hence use of the term "nanocrystal" rather than "quantum dot." --Aaron 15:31, 7 August 2006 (UTC)

Discretization of charge?

I have a problem with the following sentence: "This confinement leads to (...) and to the quantization of charge in units of the elementary electric charge e" I agree that the confinement leads to discrete levels and that the charge on the dot is a multiple of the electron charge. To me this sentence sounds however as if charge quantization was a special feature of the quantum dot, which it is not. Bamse 01:38, 8 August 2006 (UTC)

One of the "stated" applications

"Another paper, published in the October 18, 2005 issue of the Journal of the American Chemical Society, reports that Michael Bowers II at Vanderbilt University discovered that certain size crystals of cadmium and selenium emit white light when excited by an ultraviolet laser. This emission appears to be coming from the surface of the crystal, rather than the center. The crystals contain either 33 or 34 pairs of atoms. While they are being pyrolytically synthesized, they preferentially form into just this size; so Bowers can make a batch of such crystals in about an hour. Another student then mixed these quantum dots into ordinary varnish, applied it to a blue LED, and observed that the emission is yellowish-white, like a light bulb. The researchers believe that it will be possible to achieve this emission of white light via electrical stimulation as well as photonic, and hope to demonstrate it soon."

The quality of writing in this paragraph is a bit lacking, since it reads like someone's laboratory book; is it really relevant which students are involved, or how long it takes to make a batch of crystals? The ideas are ordered haphazardly and some of the sentences are plainly speculative. I suggest this paragraph be rewritten, or just removed.

146.232.75.208 15:34, 10 August 2006 (UTC)

Seems as though this section was written by the author of the article itself. This article is far from a seminal paper in the field. It should be removed.

'nerd