InxGa1−xP layers lattice matched and lattice mismatched to GaAs substrates have been grown by metalorganic chemical vapor deposition (MOCVD). Deep level transient spectroscopy, double crystal x-ray diffraction, and current–voltage measurement were employed to characterize InxGa1−xP layers and InxGa1−xP/GaAs heterojunctions. We have observed a shallow electron trap located at EC−60 meV in InxGa1−xP layers with x<0.469, and a deep electron trap at EC−0.85 eV with x≳0.532. However, no deep levels were detected in InxGa1−xP (0.469<x<0.532) layers. The deep levels, if they exist, have a concentration of less than 5×1011 cm−3 which is the lowest deep level concentration reported so far in MOCVD grown InxGa1−xP materials. This is also the first observation in which lattice mismatches ranging from −0.125% to +0.224% (0.469<x <0.532) do not generate deep levels in MOCVD grown InxGa1−xP.