Carrier transport in signal-processing-in-the-element (SPRITE) detecto
rs is an important phenomenon because it determines properties such as
the responsivity and the modulation transfer function (MTF). The prev
ious literature has presented approximate solutions to the transport p
roblem that neglect boundary effects, which have long been thought to
play a major role in SPRITE behavior. We present a new solution to the
problem through the use of modal analysis. This method intrinsically
includes boundary conditions and thus is more complete than the previo
us analysis. Furthermore we use this solution to derive expressions fo
r the MTF. The effects of the boundary conditions on the MTF are studi
ed to determine their optimum values.