A peak comprise a restricted region of a spectrum, possibly a single wavelength which is absorbed or emitted. A band comprise a more wider region which cover several wavelengths.

A peak comprise a restricted region of a spectrum, possibly a single wavelength which is absorbed or emitted. A band comprise a more wider region which cover several wavelengths.

Thank you Professor Alessandro Venditti for your good sharing.

Best regards,

Mostafa

You're welcome!

It should be also noted that in Energy terms when you have a peak there is only a single transition involved (in some cases may be the only permitted one) because at a given wavelength a given amount of energy is associated. This can also be seen considering the corpuscular theory in terms of a photon to which a given amount of energy is associated. Instead when a band (of absorption or emission) is present several transitions are involved each one with its specific quantum of energy.

Thank you so much Professor Alessandro Venditti for the fruitful information you shared. Indeed, I do appreciate that.

Best regards,

Mostafa

You're welcome!

And thanks to you too.

Why do you have TWO separate ntries for the same question of the difference of peak and band here at ResearchGate?

As "old spectroscopist" it is for me a pleasure to help you and I give you following infos about these differences :

If you consult google or the Concise Oxford Dictionnary, you 'll find for :

-Band ---- Range of frequency or wavelength in spectrum.

In UV-Vis the band is showed in Abb. 3 with a lot of transitions responsible for the broadening of the band.

- Peak ---- Highest point in curve

In UV-Vis the highest point in curve is the lambda max value

- the Abb. 2 shows a very , very , very simplified model (it doesn't occur in the nature).

It shows one transition without another effect and shows ONE LINE!!

Your paper as help for the understanding of the differences:

Journal of Molecular Liquids 248 (2017)

According to your methylene blue and zeolite paper, you can see the band of your MB dye as polyatomic molecule with the lambda max value (Peak)(according to the concentration) if you take an UV-Vis spectrum of it.

Zeolite:

On other part , I join the line spectra of Si and Al. As you can see, there are a plenty of lines for them and not ONE!!

About temperature and solvent dependance for UV-Vis or fluorescence investigations:

I join for the explanation a picture of the SHPOLSKI 's paper about fluorescence spectra of frozen solutions of 3,4-benzopyrene.

The author wrote : " The broad BANDS of the structured spectrum are resolved here into groups of sharp LINES.....

In order to understand the explanations of Alessandro and other answerers,

please consult the following book :

Introduction to Molecular Spectroscopy G.M. Barrow

International Student Edition 1962 .

I wish you and your team a successful research

JRG

Dear Professor Harry ten Brink,

Sorry about that. Actually I did not realized that. There was something wrong with my computer. Thank you anyway for your sharing.

All the best,

Mostafa

Dear Professor Jean Rene Grezes,

Thank you so much for your good sharing and fruitful information you provided. Indeed, I do appreciate that. I really have leaned from them. You really gave a very specific and clear answer.

Thank you very much again.

Best regards,

Mostafa

I think it is a personal choice with the convention that broad peaks are called band and narrow bands called peak.

what I feel when one use the the term "band"in indicates some range e.g., "a band appears in the range 200-400 nm", but the term "peak"specified some definite value corresponding to the maxima of the band.

Thank you Dr Mahmut Ruzi for your contribution.

All the best,

Mostafa

Dear Dr Sandip Kumar Saha,

Thank you so much for your answer. I do appreciate your contribution.

Best regards,

Mostafa