Polarization enhanced avalanche photodetector and method thereof

Abstract

An avalanche photodetector comprising a multiplication layer formed of a first material having a first polarization; the multiplication layer having a first electric field upon application of a bias voltage; an absorption layer formed of a second material having a second polarization forming an interface with the multiplication layer; the absorption layer having a second electric field upon application of the bias voltage, the second electric field being less than the first electric field or substantially zero, carriers created by light absorbed in the absorption layer being multiplied in the multiplication layer due to the first electric field; the absorption layer having a second polarization which is greater or less than the first polarization to thereby create an interface charge; the interface charge being positive when the first material predominately multiplies holes, the interface charge being negative when the first material predominately multiplies electrons, the change in electric field at the interface occurring abruptly at the atomic level; the interface charge creating electric field discontinuity causing first electric field to attain the breakdown field in the multiplication region and the second electric field to be low or zero in the absorption layer to thereby eliminate the need for a doped charge layer and the associated thickness of the doped charge layer required to transition from the low field to the high field. Also claimed is a method of making.