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Comment by pjc50 | Hacker News Reader

> The polycrystalline tin selenide the team makes is spiked with sodium atoms, creating what is known as a “p-type” material that conducts positive charges. To make working devices, researchers also need an “n-type” version to conduct negative charges.

This is literally inventing half a solution. Shockley didn't go to the press when he'd built half a diode.

(OK, this is snarky, but I think this is another case where people need to understand the difference between "a small but valid advancement in the art" and "actual products". As a materials science paper this is valid.)

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> Zhao’s team recently reported making an n-type single-crystal tin selenide by spiking it with bromine atoms. And Kanatzidis says his team is now working on making an n-type polycrystalline version. Once n-type and p-type tin selenide devices are paired, researchers should have a clear path to making a new generation of ultra-efficient thermoelectric generators.

So write the paper after that's all done.

You don't understand the difference btw a research paper and a product launch. A paper is to provide inspiration. In this case, a high ZT p-type crystal may indicate a new mechanism that can be applied to searching / designing new thermoelectric materials. It's not for selling you a working device that can be put in your shopping cart.

(I did research in nano thermoelectrics and published a few papers in this field)

In defense of parent though it does not say “can” or “will” convert. News and views should have reflected that so it’s really not the fault of the original paper authors.

I get the snark but this is also Science and their easy to digest news release. It is literally a science journal, not a product release or even engineering journal. I wouldn't say it really fits into the "advancement in the art," or "actual products." It is scientific progress in the material science world (which I know is your last parenthetical aspect of your comment).

Isn't graphene a high quality p type material as well?

What makes a material p or n?

Kinda answered my own question with some searching - looks like p type has lots of electrons, n type has lots of holes, and graphene oxide (GO) makes an excellent and simple to use n type material.

Graphene can be modified by changing its topology to be p or n, but GO is n by default. Do electron and hole features have to match in these constructions?

I think that's backwards: P-type has more holes than electrons, n-type has more electrons than holes.

https://simple.wikipedia.org/wiki/P-type_semiconductor (property 2)

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