Quantitative analysis of room temperature photoluminescence of c-Si wafers excited by short laser pulses

Abstract

Effect of surface nonradiative recombination on kinetics and total yield of the interband photoluminescence (PL) of $\mathrm{c-}\mathrm{Si}$ wafers excited at room temperature by short laser pulses is studied. Numerical simulations show that a correlation of the PL quenching with the surface defect density takes place even at the high excitation level in spite of Auger recombination in the bulk. The quantum yield of PL reaches some percent for Si wafers with low bulk and surface defect concentrations. The calculations are confirmed by the experimental correlation between the PL quenching with the density of interface states ${\mathrm{(D}}_{\mathrm{it}})$ at the ${\mathrm{Si/SiO}}_2$ interface which has been obtained by conventional capacitance–voltage measurements. The express characterization of the $D_{\mathrm{it}}$ of Si surfaces by the pulsed PL can be carried out for the defect density in the range from ${10}^8$ to ${10}^{14}\hspace{0.17em}{\mathrm{cm}}^{\text{−2}}$ at room temperature.