As all we know, by changing the size of perovskite nanoparticles, we can tuning of band gap would accur, so that according to each band gap we would expect photoluminescence in a certain wavelength. In lead halide perovskites, when we use bromide in the site of halogens, the luminescence will be green. In the case of CsPbBr3, we can have blue emission up to green related to size of nanobparticles. Now, if we have large particles that have luminescence, can we expect orange emission from that? (Although I've seen articles which has reported emission from micro size particles.)
For a given material, quantum effects on the tens of nanometer scale can affect the electronic properties of nanoparticles, but those properties are first and foremost governed by the nature of the material itself, its atomic/crystalline structure, and so, for example very small nanoparticles of for example CdSe and oragnge/red, whereas, size has little or no effect on the electronic properties of polymeric nanoparticles.
Perovskite is the crystal structure that quantum dots possess, also called perovskite quantum dots (QDs). It is a new class of QDs. The band gap energy of QDs does vary with its size due to quantum confinement. There is an intensive discussion on the research gate forums. Please see the link
https://www.researchgate.net/post/Why_does_band_gap_energy_of_quantum_dots_vary_with_its_size2
Hope it helps.
Recently,I synthesized CsPbBr3 by easily grinding with CsBr and PbBr2 without luminous. The partical was about 500nm. However I changes try other source by easily grinding also synthesized CsPbBr3 with high green luminance.The particals ranges from50 to800nm. The luminance can be attributed to the NCs? Does this easily grind have a value for continue research?
Dear Nima,
welcome,
I congratulate you for these interesting results. These are very expressive for the effect of grain size on the energy gap and can be used to demonstrate it.
AS for the answer of the question the quantum size confinement effect can be reduced rapidly with the grain size such it is expected that you increase the grain size more than 11 nm you will not get an appreciable reduction in the energy gap.
This what found by the colleague Long when increased the grain size by many factors he got green luminescence.
So, accordingly you will not reach the intended by further increasing the grain size. You can check this by knowing the band gap of the bulk material.
Best wishes
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