Porous silicon luminescence study by defect imaging methods

摘要

Porous silicon properties were investigated employing mapping and imaging techniques. With an atomic force microscope, we have established cases where blue shifts of luminescence and surface photovoltage threshold coincide with decreasing pores diameter. More importantly, we have also established unambiguous cases where blue shift took place for increasing pores diameter. The latter observation is strong proof that the quantum size effect is not the only luminescence mechanism. Our data implies that a dominant luminescence band is often of chemical origin.