Numéro
Le Journal de Physique IV
Volume 03, Numéro C5, Octobre 1993
Third International Conference on Optics of Excitons in Confined
Page(s) C5-315 - C5-318
DOI http://dx.doi.org/10.1051/jp4:1993564
Third International Conference on Optics of Excitons in Confined

Le Journal de Physique IV 03 (1993) C5-315-C5-318

DOI: 10.1051/jp4:1993564

Experimental evidence of exciton wavefunction shrinkage in InxGa1-xAs/InP multi quantum wells

B. ROTELLI1, C. ARENA1, L. TARRICONE1 and C. RIGO2

1  Dipartimento di Fisica, viale delle Scienze, 43100 Parma, Italy
2  CSELT, via G. Reiss Romoli 274, 10184 Torino, Italy


Abstract
We have studied the confinement effect on the ground state of the n=1 heavy exciton in InxGa1-xAs/InP Multi Quantum Wells (MQW) grown by Chemical Beam Epitaxy (CBE). Absorption optical spectra obtained in the excitonic region on several MQW were analyzed as a function of the well thickness Lz, ranging in the interval 25-80 Å, and as a function of the temperature (8-300 K). In agreement with the theory, a clear enhancement of the oscillator strength calculated by the integrated area of the heavy exciton absorption peak with the well thickness decrease, has been observed ; such increase is a direct evidence of the exciton wavefunction shrinkage and is one of the firstly reported in InxGa1-xAs/InP MQW. The ratio between 1s light and heavy exciton absorption area was used to evaluate their related reduced mass ratio µlhhh = 1.36±0.075 in excellent agreement with the calculated one (1.35).



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