Effect of Te doping on electron traps in In_0.5Ga_0.5

Abstract

The formation of electron traps in undoped and Te-doped $In_{0.5} Ga_{0.5} P$ layers grown on GaAs substrates by vapor phase epitaxy is investigated by deep level transient spectroscopy, thermally stimulated capacitance, and secondary ion mass spectrometry measurements. All the Te-doped layers are characterized by a new electron trap with an activation energy of 0.16±0.02 eV, which density is proportional to the Te atom concentration, and its thermal equilibrium occupation appears to be very small. The second electron trap observed in both undoped and Te-doped layers has the same characteristics as a well-known electron trap associated with S or Si donors, which are the residual impurities in the studied layers. Furthermore, Te doping suppresses the persistent photocapacitance observed in the undoped layers.