Diethyl gallium chloride (DEGaCl) was employed as an alternative gallium precursor in the epitaxial growth of GaN for producing a hydride vapor-phase epitaxy (HVPE)-like growth chemistry in a metal-organic vapor-phase epitaxy (MOVPE) system. The standard 'two-step' GaN growth process was carried out using this Cl-containing precursor and compared to the conventional growth using trimethyl gallium (TMGa) source under identical reactor conditions. The growth rate during DEGaCl-based growth decreases with increasing temperature, indicating that the growth front may be close to local thermodynamic equilibrium. A direct comparison of materials properties associated with these precursors in various structural combinations of buffer and high-temperature GaN epilayers was performed. Improved material properties and a significant difference in the surface morphology were observed in the case of DEGaCl-based high-temperature growth, as determined by X-ray diffraction, capacitance-voltage, atomic force microscopy and photoluminescence measurements. We attributed the improved growth behavior to the 'nearer-to-equilibrium' growth front that could result from the presence of HCl-related etching reactions.