AlSb multiple quantum well structures

A43 1 J.M. WORLOCK Bell Communications Received

* Research, Holmdel, New Jersey 07733, USA

29 July 1985; accepted

for publication

15 September

1985

We investigate the effect of magnetic fields on the intensity of photoluminescence in GaAAlGaAs n-type modulation-doped multiple quantum well heterostructures. An overall increase in luminescence is observed with increasing axial field. Large oscillations in the intensity occur whose peaks and valleys are approximately periodic in l/B. They cannot be correlated with Shubnikov-de Haas oscillations but possibly show an empirical relation with Landau level crossings of the lowest unoccupied subband states.

143

Surface Science 174 (1986) 143-147 North-Holland, Amsterdam

SIZE-INDUCED DIRECT-TO-INDIRECT GAP TRANSITION GaSb/ AlSb MULTIPLE QUANTUM WELL STRUCTURES A. FORCHEL,

U. CEBULLA

IN

and G. TRiiNKLE

4. Physikalisches Institut, Universitiit Stuttgart, PF 801140, D-7000 Stuttgart-80, Fed. Rep. of Germany

and H. KROEMER,

S. SUBBANNA

and G. GRIFFITHS

University of California, Santa Barbara, California 93106, USA Received

30 July 1985; accepted

for publication

12 October

1985

Using excitation spectroscopy we have investigated the size-induced cross-over from direct to indirect bandstructure in GaSb/AlSb quantum wells. In samples with L, < 30 A we observe in particular the emission from the indirect and the direct energy gap of the wells, whereas for larger L, only the direct transition occurs. Time-resolved measurements yield a change of the carrier lifetime by about a factor of 100 at the cross-over.

Surface

148

Science 174 (1986) 148-154 North-Holland, Amsterdam

PROPERTIES OF 2D QUANTUM WELL LAiERS J. NAGLE, S. HERSEE, M. RAZEGHI, M. KRAKOWSKI, B. DE CREMOUX and C. WEISBUCH Laboratoire Central de Recherches Thomson-CSF, B.P.10, 91401 Orsay, France Received

1 August

1985; accepted

for publication

Domaine de Corbeville, 11 October

1985

The lasing characteristics of quantum well and double heterostructure lasers are compared for the GaAs/GaAlAs and GaInAs/InP materials systems. The poorer performance of GaInAs/InP quantum well lasers is shown to be due to carrier heating linked to Auger recombination. However, low-temperature measurements reveal that in other respects these lasers are well behaved.