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 c-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 (Dit) at the Si/SiO2 interface which has been obtained by conventional capacitance–voltage measurements. The express characterization of the Dit of Si surfaces by the pulsed PL can be carried out for the defect density in the range from 108 to 1014 cm−2 at room temperature.

Electrochemical stabilization of crystalline silicon with aromatic self‐assembled monolayers in aqueous electrolytes

“…), and the photoluminescence signals at hν PL = 1.1 eV were collected by a silicon photodiode (time constant ~ 1 µs) at room temperature [31,32]. Photovoltage transients were measured using an InGaAs light emitting laser diode (λ = 903 nm, W = 1 × 10 -2 mJ cm -2…”

“…was taken as a calibration standard for calculating the surface defect density [36]. The surface defect density can be calculated from the characteristic time constant of the measured transient according to the model previously reported [32]. In comparison to the poorly passivated surface with wet chemical oxide…”

Electrochemical Passivation and Modification of c-Si surfaces

“…For this purpose, in-situ techniques are required to measure sensitively and fast the surface recombination velocity or the surface defect concentration. Such techniques are pulsed photoluminescence (PL) spectroscopy [4,5] and surface photovoltage (SPV) measurements [6]. Additionally, there is need for processing schemes which can be performed at ambient conditions, i.e.…”

Initial stages of porous silicon formation: An in‐situ investigation of the electronic properties and surface morphology

“…Nonradiative surface recombination and charging of Si surfaces can be investigated in-situ by the pulsed photoluminescence (PL) and photovoltage (PV) techniques, respectively. The radiative band to band recombination of c-Si is controlled by nr surface recombination if the bulk lifetimes of minority charge carriers are very long (longer than 10 µs) [44]. At fixed excess carrier concentrations, the PV signal is given by the band bending, i.e.…”