Electroluminescence of composite channel InAlAs/InGaAs/InP/InAlAs high electron mobility transistor

An experimental investigation of impact ionization by electroluminescence i n composite channel lattice-matched InAlAs/InGaAs/InP/InAlAs high electron mobility transistors (HEMTs) is presented. In these transistors, an InP sub channel layer is added to the InGaAs channel. Radiative recombinations at t wo different energies are observed, characteristic of recombinations in the InGaAs channel and at the InP/AlInAs interface. The bias-dependent electro luminescence line intensities are used to analyze the role played by the In P layer for relaxing the hot carriers. A large fraction of electrons in the InGaAs channel of the composite HEMT is transferred to the InP subchannel in the high field gate-drain region. (C) 2000 American Institute of Physics . [S0021-8979(00)06105-3].