To address the growing demand for high-performance photoconductive materials compatible with fiber-based 1550 nm lasers in terahertz photoconductive antennas, this study systematically investigates the growth and physical properties of low-temperature Fe-doped InGaAs (InGaAs:Fe) films fabricated by solid-source molecular beam epitaxy. A series of InGaAs:Fe films with varied Fe doping concentrations were epitaxially grown on semi-insulating InP:Fe substrates, aiming to optimize the electrical and optical characteristics required for efficient terahertz generation and detection. The experimental approach combined advanced materials characterization with electrical and ultrafast optical measurements. The Fe doping level was precisely tuned by controlling the Fe source temperature from 1090 ℃ to 1120 ℃, yielding estimated doping concentrations ranging from ~3.9×10¹⁹cm^-3 to 6.9×10¹⁹cm^-3. High-resolution X-ray diffraction and transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy were employed to examine the crystalline quality, microstructure, and elemental distribution. Electrical properties were evaluated using room-temperature Hall effect measurements, and carrier dynamics were probed via femtosecond transient reflectance spectroscopy. The structural analysis confirmed that InGaAs:Fe films grown at Fe source temperatures up to 1114 ℃ exhibit high crystalline perfection without detectable phase separation or Fe clustering. However, at 1120 ℃, Fe-rich nanoclusters form, leading to phase separation and degraded crystal quality. High-resolution X-ray diffraction rocking curves and lattice parameter evolution further indicated that Fe incorporation influences the lattice strain through a combination of substitutional and interstitial occupancy, with optimal structural coherence observed at intermediate doping levels. Electrically, the films show a strong doping-dependent behavior. As the Fe concentration increases, the carrier concentration drops sharply from ~10¹⁶cm^-3 to ~10¹³cm^-3, while the resistivity rises from tens to hundreds of Ω·cm and the electron mobility improves significantly. The sample grown at an Fe source temperature of 1108 ℃ (corresponding to Fe ≈ 6.0×10¹⁹cm^-3) delivers the best overall performance: a low carrier concentration of 2.05×10¹³cm^-3, a high resistivity of 381.82 Ω·cm, and a high electron mobility of 796.89 cm²/(V·s). Moreover, this sample maintains N-type conductivity, which is essential for terahertz photoconductive antenna operation. Femtosecond pump–probe measurements revealed an ultrashort carrier lifetime of 0.65 ± 0.01 ps, comparable to state-of-the-art materials grown by gas-source molecular beam epitaxy, confirming the suitability of solid-source molecular beam epitaxy-grown InGaAs:Fe for ultrafast photoconductive applications. In conclusion, this work demonstrates that solid-source molecular beam epitaxy is a capable and safe technique for producing high-quality Fe-doped InGaAs films with tailored electrical and transient optical properties. The optimized InGaAs:Fe film with Fe ≈ 6.0×10¹⁹ cm^-3 simultaneously fulfills the key requirements for terahertz photoconductive antennas: high resistivity, high mobility, N-type conductivity, and sub-picosecond carrier lifetime. These results provide a reliable materials platform for the development of compact, high-sensitivity, and broadband terahertz systems operating at the telecommunications wavelength of 1550 nm.