Close spaced vapor transport (CSVT) epitaxial layers have been grown under water vapor partial pressurepranging from 5×10−2to 5 mm Hg for source temperatures of 800 and 850 °C and a substrate temperature of 730 °C, using undoped high‐purity GaAs as source material and ⟨100⟩ chromium doped high‐resistivity GaAs as substrate. From Hall measurements, all layers were found to ben‐type with a majority carrier concentration in the range of (2–3) ×1017cm−3and a mobility 3100–3600 cm2 V−1 s−1aspvaries from 5.0 to 5×10−2mm Hg. Photoluminescence measurements show the following dominant recombination processes: an exitonic peak at 1.514 eV, a free band acceptor at 1.498 eV, a donor acceptor at 1.490 eV, and two peaks involving complexes at 1.47 and 1.42 eV. These peaks depend on the water vapor pressure: for low values ofponly the exitonic peaks exist; aspincreases the photoluminescence becomes less efficient until it disappears forp=5.0 mm Hg. This study shows that CSVT‐GaAs epilayers grown under proper conditions have high quality and could be used for producing some electronic devices.