What is the band gap of CdSe quantum dots?
What is the band gap of CdSe quantum dots?
The UV- Vis absorbance peaks indicate the broad absorption behavior of the synthesized CdSe quantum dots. The calculated band gap energy was 2.55 eV and further it is found the particle size estimated from the maximum excitonic peaks for CdSe 2.7 nm.
What is the relation between quantum confinement and Bohr exciton radius of a semiconductor quantum dots?
Quantum confinement is experienced by the semiconductor crystals with size less than twice the Bohr radius of the excitons (i.e., electron-hole pairs).
What is the size of quantum dot?
2-10 nanometers
Quantum dots are tiny particles or nanocrystals of a semiconducting material with diameters in the range of 2-10 nanometers (10-50 atoms).
What are cadmium selenide quantum dots?
Overview. CdSe quantum dots (QDs) are produced by simultaneously injecting cadmium (Cd) and selenium (Se) precursor solutions into a heated growth solution of octadecene in ambient atmosphere. Once combined, Se and Cd form CdSe clusters that become continually growing QDs as the reaction progresses.
Is CdSe stable?
Furthermore, we find that type I CdSe/CdS/ZnS QDs are fairly stable during the thermal annealing process of a QD–SiO2/Al2O3 monolith (SAM) phosphor, but quasi-type II CdSe/CdS QDs easily lose their emission possibly because the delocalized electrons to the shell are more susceptible to being captured by the surface …
Are CdSe semiconductor nanocrystals actually semiconductors?
This work is focused on the studying of CdSe semiconductor nanocrystals. These nanocrystals are considered as one of the most widely studies semiconductors because of their size – tunable optical properties from the visible spectrum.
Does quantum confinement reduce band gap?
The bandgap energy of the quantum dot increases with the reduction of its size because of the quantum confinement.
What is exciton Bohr diameter?
Exciton Bohr radius can be defined as the separation distance between electron and hole. We all know that the charge carriers can move freely in bulk semiconductor, thus the wavefunction looks much like a hydrogen atom.
Why does band gap energy of quantum dots vary with its size?
For a quantum dot, the length of the box is actually its size. So, with decrease in size (i.e., with decrease in the length of the box), the energy gap will increase and with increase in size the reverse will happen. This is primarily the reason behind the dependence of the band gap energy of quantum dots on its size.
What type of semiconductor is CdSe?
II-VI semiconductor
Cadmium selenide is an inorganic compound with the formula CdSe. It is a black to red-black solid that is classified as a II-VI semiconductor of the n-type. Much of the current research on this compound is focused on its nanoparticles.
What is the formula for cadmium selenide?
CdSeCadmium selenide / Formula