Real-space transfer (RST) light-emitting devices are implemented with a strained GaAs/InGaAs/GaAs quantum well heterostructure fabricated on GaAs substrates. The device energy band diagrams are simulated by using theMEDICIprogram. The effects of critical thickness, quantum size, and strain-induced band-gap shift on the optical transition energies at 77 and 300 K are calculated. Photoluminescence (PL) measurement is carried out to characterize the RST light-emitting devices. The measured results agree well with calculated values. The narrowest full widths at half-maximum of PL spectra are measured to be 17 meV at 300 K and 9 meV at 77 K for an undopedGaAs/In0.2Ga0.8As/GaAsquantum well heterostructure. The PL spectra confirm that the emission is dominated by emission from the strained GaAs/InGaAs/GaAs quantum well. ©1997 American Institute of Physics.