Our work demonstrates through DFT calculations that quantum dots in a superlattice or "quantum dot solid" will generally maintain the quantum confinement for which they are famous. Additionally, we investigated different superlattice-types and found that a cubic superlattice has a superior electron mobility. This is a little surprising since the majority of papers I have seen only discuss two phases for colloidal PbS QD superlattices: FCC and BCC. (There are some papers out there that have looked at solid PbSe QD superlattices so the cubic phase is possible to create.) A cubic superlattice allows neighboring QDs to have enhanced wave function overlap through the fusing facets. The (111) facets in the FCC and BCC phases block the wave function and so do not allow good transport. Our work demonstrates that it can be important to give some thought to the surface physics of different facet-types and how those facets are interconnected in order to allow optimal carrier transport.
Bandlike Transport in PbS Quantum Dot Superlattices with Quantum Confinement
New paper out in Journal of Physical Chemistry Letters!
Our work demonstrates through DFT calculations that quantum dots in a superlattice or "quantum dot solid" will generally maintain the quantum confinement for which they are famous. Additionally, we investigated different superlattice-types and found that a cubic superlattice has a superior electron mobility. This is a little surprising since the majority of papers I have seen only discuss two phases for colloidal PbS QD superlattices: FCC and BCC. (There are some papers out there that have looked at solid PbSe QD superlattices so the cubic phase is possible to create.) A cubic superlattice allows neighboring QDs to have enhanced wave function overlap through the fusing facets. The (111) facets in the FCC and BCC phases block the wave function and so do not allow good transport. Our work demonstrates that it can be important to give some thought to the surface physics of different facet-types and how those facets are interconnected in order to allow optimal carrier transport.
Our work demonstrates through DFT calculations that quantum dots in a superlattice or "quantum dot solid" will generally maintain the quantum confinement for which they are famous. Additionally, we investigated different superlattice-types and found that a cubic superlattice has a superior electron mobility. This is a little surprising since the majority of papers I have seen only discuss two phases for colloidal PbS QD superlattices: FCC and BCC. (There are some papers out there that have looked at solid PbSe QD superlattices so the cubic phase is possible to create.) A cubic superlattice allows neighboring QDs to have enhanced wave function overlap through the fusing facets. The (111) facets in the FCC and BCC phases block the wave function and so do not allow good transport. Our work demonstrates that it can be important to give some thought to the surface physics of different facet-types and how those facets are interconnected in order to allow optimal carrier transport.