Hydrogenated amorphous germanium films were deposited by thermal dissociation of undiluted germane. The optical and electronic properties of the material were investigated using infrared spectroscopy (IR), photothermal deflection spectroscopy, spectroscopic ellipsometry, and conductivity measurements. The results show that homogeneous material with steep band tails (50 meV) and without any sign of postoxidation can be obtained. A strong correlation between the defect density and the IR Ge–H stretching modes is observed.