Observation of negatively charged excitons X- in semiconductor quantum wells
Abstract
The negatively charged exciton X- is identified by its circular polarization properties in 1.7 K magentoabsorption spectra of CdTe/Cd1-xZnxTe multiple quantum wells modulation doped with electron concentrations Ns~=2×1010 to 1.5×1011 cm-2. The binding energy of the second electron of X- is 0.20 3D Rydbergs at 100 Å well width. The species X- and the neutral exciton X exist in zero field for low Ns. At Ns=1.45×1011 cm-2 a Fermi edge singularity is seen at B=0 but X- appears with field, at filling factor ν=2, while X appears at ν=1.
- Publication:
-
Physical Review Letters
- Pub Date:
- September 1993
- DOI:
- 10.1103/PhysRevLett.71.1752
- Bibcode:
- 1993PhRvL..71.1752K
- Keywords:
-
- 78.66.Fd;
- 71.35.+z;
- 73.20.Dx;
- 78.20.Ls;
- III-V semiconductors;
- Magnetooptical effects