Chapter 4 Properties of nanomaterials
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EXCITONIC EFFECTS IN QUANTUM WELLS<br />
(a), In which the Bohr radius <strong>of</strong> the exciton is<br />
much smaller than the quantum well width,<br />
and the one in (b), for which the width <strong>of</strong> the<br />
well is smaller than aB.<br />
Exciton binding energy as a func;on <strong>of</strong> the<br />
quantum well width.<br />
(a) Exciton orbits in a very bulk crystal;<br />
(b) the spherical form <strong>of</strong> the exciton<br />
becomes elongated when the width <strong>of</strong><br />
the QW is smaller than the exciton<br />
radius.<br />
Binding energies for holes in a GaAs–AlGaAs<br />
quantum well as a func;on <strong>of</strong> well width.<br />
Aver [5].