<title>Excitonic effects and luminescent properties of narrow-gap Hg1-xCdxTe</title>

We present a study of the excitonic luminescence contribution in Hg_1-xCd_xTe for a wide CdTe mole fraction range (0.23 < x < 0.97). This mixed crystal semiconductor system is relatively well understood and offers a unique possibility to study the contribution of excitons to the luminescence of a material with a continuously decreasing energy gap. This reexamination is based on a set of uniform (carrier concentration, degree of compensation) samples grown by the traveling heater method. Furthermore the luminescence from Hg_0.15Cd_0.85Te/Hg_0.7Cd_0.3Te superlattices is analyzed with respect to the luminescence contributions of confined 2D excitons.