ENHANCED AMBIPOLAR INPLANE TRANSPORT IN AN INAS GAAS HETERO-N-I-P-I/

In-plane transport in an InAs/GaAs semiconductor hetero-n-i-p-i has be en investigated using picosecond transient grating techniques and an o rder-of-magnitude enhancement of the ambipolar transport relative to t hat measured in a similar undoped sample has been demonstrated. Both t he magnitude and the density dependence of this enhanced transport are consistent with an additional driving force that is associated with a n in-plane modulation of the screened n-i-p-i field. This modulation i s the result of the spatial separation by perpendicular transport of e lectrons and holes that also have an in-plane density modulation.