Extended excitons and compact helium-like biexcitons in type-II quantum dots

Details Extended excitons and compact helium-like biexcitons in type-II quantum dots Extended excitons and compact helium-like biexcitons in type-II quantum dots

2009-10-22

arxiv.org/abs/0910.4290v1

Physics

Condensed Matter

Mesoscale and Nanoscale Physics

Scientific paper

We have used magneto-photoluminescence measurements to establish that InP/GaAs quantum dots have a type-II (staggered) band alignment. The average excitonic Bohr radius and the binding energy are estimated to be 15nm and 1.5 meV respectively. When compared to bulk InP, the excitonic binding is weaker due to the repulsive (type-II) potential at the hetero-interface. The measurements are extended to over almost six orders of magnitude of laser excitation powers and to magnetic fields of up to 50 tesla. It is shown that the excitation power can be used to tune the average hole occupancy of the quantum dots, and hence the strength of the electron-hole binding. The diamagnetic shift coefficient is observed to drastically reduce as the quantum dot ensemble makes a gradual transition from a regime where the emission is from (hydrogen-like) two-particle excitonic states to a regime where the emission from (helium-like) four-particle biexcitonic states also become significant.

Affiliated with

Also associated with

No associations

Rating

Extended excitons and compact helium-like biexcitons in type-II quantum dots does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Extended excitons and compact helium-like biexcitons in type-II quantum dots, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Extended excitons and compact helium-like biexcitons in type-II quantum dots will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-690791