A GaAs/InGaAs quantum-well structure was grown by low-pressure metalorganic chemical vapor deposition (LP-MOCVD). The quantum well was graded from 25% to 15% indium (from the bottom to the top of the channel). Hall measurements were made to characterize the concentration and mobility of the two-dimensional electron gas (2DEG). The temperature-dependent photoluminescence (PL) and photoreflectance (PR) spectra of the structure of interest were obtained. Various intersuband features were observed in the PR spectra. Furthermore, a 1.5μm gate-length high-electron mobility transistor (HEMT), fabricated on these layers, had an extrinsic transconductance of 127mS/mm. The optical and electrical characteristics were determined simultaneously.