Coupling in physics generally means interaction. The best example from classical mechanics is two pendulums connected (coupled) with a string. In case of semiconductors you may say that pn junction is a good example of coupling. There is a lot of papers about semiconductor quantum dots coupling.

Substituting is one mechanism of doping but you can also dope materials using interstitial mechanism so doping is definitely not the same as substituting. Furthermore dopants are usually added in small concentrations and thus they generally do not form a new phase. If you mix two semiconductor you usually form a new phase.

Coupling in physics generally means interaction. The best example from classical mechanics is two pendulums connected (coupled) with a string. In case of semiconductors you may say that pn junction is a good example of coupling. There is a lot of papers about semiconductor quantum dots coupling.

Substituting is one mechanism of doping but you can also dope materials using interstitial mechanism so doping is definitely not the same as substituting. Furthermore dopants are usually added in small concentrations and thus they generally do not form a new phase. If you mix two semiconductor you usually form a new phase.

While Paweł above has answered your question very well, I would like to add that the term "doping", when referring to semiconductors has a rather precise meaning.

When talking about inorganic semiconductors, doping means any process through which substances that are more electron-rich or electron-defficient than the base material are introduced into the structure of the base material.

In the case of organic semiconductors, doping is used to denote the introduction of charges into the conducting organic materials through reduction (n-doping) or oxidation (p-doping).

thank u dear Paweł Piotr Michałowski and Tomasz Jarosz for ur answers. i have coupled ZnO with low concentaration of silver oxide, but in XRD results there is no peak due to silver oxide all peaks develp to ZnO but EDX results confrm that ZnO and Ag2O both are presents. As i have mentioned that it is coupling then Why silver oxide peaks are not appeared in XRD results

Dear Ali Hammad, EDX is used for the elemental analysis so that is why you see both Zn and Ag. In case of XRD you have to form additional phase to see silver oxide contribution. If the concentration is too low you won’t see anything new. The other possibility is that your measurement is too noisy and you can’t distinguish the signal coming from silver. Try running a longer experiment and see if it helps. Regards!

once again thank u so much dear Paweł Piotr Michałowsk. As the crystallinity and concentration of Ag2O is low as compare to ZnO, is it possible that Ag2O peaks emerg with ZnO if the experiment is running smoth??

Additional to Pavels answer to be monitorable in XRD the AgO phase have to be crystalline (XRD of nanopowder is often not so easy due to the broad signals, tempering might help.). ZnO tents to reduce the Ag+ resulting in Ag Metall. You might be able to monitor the permanent darkening of the sample if you illuminate the sample in presence of a hole reactive species ( as performed for example in the publication)

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