Modulation transfer function and quantum efficiency correlation at long wavelengths (greater than 800 nm) in linear charge coupled imagers.

The spectral modulation transfer function (MTF) of several architecturally identical commercial linear silicon charge coupled imagers (CCIs) was measured and compared to an MTF theory that included the effects of detector aperture and lateral diffusion in one dimension. A successful match between experimental data and theory was possible for proper choices of the detector aperture function and minority carrier lifetime. Long-wave (> 800-nm) MTF and spectral quantum efficiency (QE) data were very well correlated over the set of CCIs that were measured, indicating the key role of carrier lifetime (or equivalently carrier diffusion length) in determining both characteristics. This correlation was verified by exercising the MTF and QE models, tailored for the CCIs devices, with carrier lifetime as one of the free parameters.