Laser-induced, time-resolved charge-collection measurements for In0.33Ga0.76Sb p-channel MOSFETS are reported for two different device structures; a buried-channel (quantum well) and surface-channel design. The charge-collection transient response is reported for different gate bias conditions. The two structures reveal dramatically different charge-collection transient response. The buried-channel MOSFET exhibits a slowly relaxing decay component that can persist on the order of microseconds, whereas the surface-channel MOSFET has a transient response that decays within ∼ 5 ns. The slowly-relaxing decay component previously has been associated with a charge enhancement processes that are eliminated in the surface-channel design. The collected charge is reduced by ∼ 2 orders of magnitude in the surface-channel device, making this design a very attractive candidate for space applications.