GO FIGURE As the size of the quantum dots decreases, does the wavelength of the emitted light increase or decrease? Size of CdSe quantum dots 2 nm →7 nm 2.7 eV 2.0 eV Band gap energy, Eg A FIGURE 12.44 Photoluminescence. When illuminated with ultraviolet light, these solutions, each containing nanoparticles of the semiconductor CdSe, emit light that corresponds to their respective band gap energies. The light emitted depends on the size of the CdSe nanoparticles.
In cancer imaging why do quantum dots fluorescence only in the cancer cells and what causes the quantum dots to fluorescence in cancer imaging?
1) If the reaction continues for a long time, i.e, the quantum dots grow increasingly large, how do thier optical properties evolve accordingly? 2) why are quantum dots emission peaks very broad?
The spec sheets for Lumidot quantum dots from Sigma-Aldrich scientific supply company specifies the following core sizes (radius of the quantum dots) and wavelengths for their various dots: Radius (nm) wavelength(nm) 3.0 510 3.3 530 3.4 560 4.0 590 5.2 610 6.3 640 Use this data to verify that the 1/R2 dependence of Eph = Eg + n (h2/(8meR2) and to find the band gap energy (Hint: calculate Eph for each of these wavelengths, the plot Eph versus 1/R2 )
write brief notes on nodal anatomy and its systematic value for plants
17.- What quantum dots are useful for? 18.- Which is the probable mechanism of substitution for the octahedral Co(CO)to form Co(CO)s(py) (py-pyridine) 19.- Name the two compounds in the former question (question 18) 20.- draw the bond between Pt-Co the sigma and the pi components
For CdTeCdTe quantum dots, the emission wavelength increases from 540. nmnm to 755 nmnm as the dot diameter increases from 3 to 9 nmnm. Calculate the band-gap energy for the first particle diameter (3 nmnm). Express your answer with the appropriate units.
Discuss some frameworks for representing polarisation states. In particular, write brief notes on s- and p- polarisation, Jones vectors, and Mueller matrices.
describe in brief key application of principles of quantum mechanics in chemical bonding, spectroscopy, and molecular interactions.
1)Write brief notes on any two of the following: a) bryophytes b) ferns c) gymnosperms d) angiosperms 100 marks 2)What is a dichotomous key, and how can it be used in the study of plant diversity? 100 marks about 2 pages each question. thank you