I quite did not understand the first part of your question... however electrons and holes can be trapped in defect and recombine and add to dark current or overalls degrade the device performance . Surface recombination velocity shows the speed rate in which electrons and holes get recombined at the surface of semiconductor. The recombination can also happen in the bulk of the material but chances are higher at the surface due to dangling bonds and other crystal defects at the surface.

Thank You Amirhossein Ghods for help.In first part I want to ask if there exist a trap state or defect than it indicate a charge carrier in every condition or not?

In second part answer I don't understand speed rate physically.May you clarify that.