Charge transfer inHg1−xCdxTe-CdTe heterostructures

We present far-infrared magnetoabsorption experiments performed at 1.6 K in ${\mathrm{Hg}}_{1-x}{\mathrm{Cd}}_x\mathrm{Te}$-CdTe heterojunctions. The results show that a two-dimensional electron gas is formed in the ${\mathrm{Hg}}_{1-x}{\mathrm{Cd}}_x\mathrm{Te}$ layer at the ${\mathrm{Hg}}_{1-x}{\mathrm{Cd}}_x\mathrm{Te}$-CdTe interface. The electron effective mass of the two populated subbands is obtained and compared to previous theoretical calculations. We believe that the electron transfer across the interface corresponds to a new mechanism involving deep traps in the CdTe layers.