Can We Have Less Than One Exciton? Understanding Electron-Hole Pairs

[ordinary_girl]

hi

I always heard my lecturer mentioned about 'less than 1 exciton'. as everybody knows, exciton is electron-hole pair. can we have <<<1 exciton? What does it mean?
thanks in advance for your reply.

 

[kanato]

Are they referring to less than 1 exciton per unit cell? A small number of excitons in a large crystal would be much less than 1 exciton per unit cell.

 

[0xDEADBEEF]

How do you expect anyone to answer this without more context?

 

[ordinary_girl]

hi
thanks for the replied.
sorry for lack of information.

it's about exciton in quantum dot (more specificly is in type-II quantum dot where the holes is confined in the dots). from photoluminescence of power dependence, they found 2 different slope by plotting the graph of QD peak vs laser power. at low power, the slope is small due to <<<1 exciton in dots. at high power, the slope is high (starts to have biexciton). however, this can be confirmed by doing photoluminescence in magnetic field.

i am not understand the terms of '<<<1 exciton' (where from the definition, e-hole = exciton. i reckon 1exciton=1 pair of e-hole).

would appreciate for a reply.
thanks very much

 

[hiyok]

Likely, what is mentioned by your lecturer is what was said by kanat