We present experimental results on the growth and characterization of n-type InGaAs/InP quantum-well intersubband photodetectors for use at 8.93 μm. High-quality InGaAs/InP multiple quantum wells were grown by gas source molecular beam expitaxy, and then characterized by double-crystal x-ray diffraction and cross-sectional transmission electron microscopy. Based upon the structural parameters determined by these methods, the photocurrent response spectra were simulated using a six-band effective bond-orbital model. The theoretical results are in excellent agreement with experimental data. Additional important device characteristics such as dark current, spectral response, and absolute responsivity are also presented.