Electrical and optical properties of rare earth dopants (Yb, Er) in n-type III-V (InP) semiconductors

Rare earths (REs) diluted into MBE grown and synthesised n-type InP samples create an acceptor-like level (at 30 meV for Yb and 60 meV for Er) below the conduction band; the activation energies are deduced from temperature dependent Hall effect measurements. From EPR experiments where the authors observe resonance due to the Yb 3+ ground state in n-type samples, they deduce that this acceptor-like level is not the Yb 2+ /Yb 3+ acceptor level. They propose that the RE creates an attractive potential for electrons in III-V semiconductors. They discuss the consequences of this property for the luminescence excitation mechanism of the luminescence.