  We have studied the optical and electrical spectra from an n i p LED as a
function of magnetic field. This sample incorporated three GaAs quantum wells
in the intrinsic region. This device had excess n type doping and as a result.
The quantum wells were populated by a two dimension Landau electron gas. The
broad B0 field emission band evolved into a series of discrete features in the
presence of a magnetic field. These were identified as interband transitions
between the different values of l. Landau levels associated with the sub-bands,
with the selection rule. An energy splitting between the two polarised
components was observed for each Landau level transition. This was found to be
equal to the sum of the conduction and valence band spin splittings. We used
the know value of electron g factor to determine the valence band spin
splittings. Our experimental values were compared to the numerically calculated
values and were found to be in reasonable agreement.
