InGaP/GaAs heterostructures and InGaP/In0.2Ga0.8As pseudomorphic high electron mobility structures were grown by solid source molecular beam epitaxy using valved arsenic and phosphorus sources. At 450 degrees C abrupt arsenic/phosphorus heterojunctions were obtained. Charge transfer was demonstrated at both normal and inverted InGaP/GaAs heterojunctions. From capacitance-voltage profiling measurements the InGaP/GaAs conduction band discontinuity was determined to be 0.15 eV with an interface charge density of 8 x 10(10) cm(-2). Consistent with a moderate conduction band discontinuity, single pulse doped In0.5Ga0.5P/In0.2Ga0.8As structures were grown with a channel sheet density of 1.5 x 10(12)cm(-2). Double pulse doped InGaP/AlGaAs/In0.2Ga0.8As/AlGaAs structures were also grown incorporating AlGaAs donor layers and an InGaP Schottky layer. Appropriate for power devices, high sheet densities (3.5 x 10(12) cm(-2) at 77 K) and high mobilities (6620 cm(2)/V s at 300 K; 16920 cm(2)/V s at 77 K) were obtained. The InGaAs quantum well photoluminescence intensity was enhanced from the lower surface recombination velocity of InGaP compared to that of AlGaAs. No degradation of AlGaAs quality was observed by incorporating InGaP and AlGaAs into the same structure by solid source molecular beam epitaxy.