Boron-oxygen related light-induced degradation of Si solar cells: Transformation between minority carrier traps and recombination active centers

Phosphorous Diffusion Gettering of Trapping Centers in Upgraded Metallurgical‐Grade Solar Silicon

“…However, the blue square points clearly deviate from linearity (mind the log-scale). This deviation is well understood as the result of trapping effects, as explained elsewhere 13 . The PC measuraments could be satisfactorily fitted with a twoexponential function of the form y=A 1 •exp(-x/t 1 )+A 2 •exp(-x/t 2 ) with characteristic decay times t 1 and t 2 .…”

“…This deviation is well understood as the result of trapping, as explained in other studies. [14,18] The PC measuraments could be satisfactorily fitted with a two-exponential function of the form y ¼ A 1 exp(Àx/t 1 ) þ A 2 exp(Àx/t 2 ), with characteristic decay times t 1 and t 2 . The first exponential function represents physical processes that occur in the time lapse of the flash, such as SRH recombination of the measured sample (t 1 % t flash ), whereas the second one represents events that last longer, such as the ones governed by slow traps.…”

“…In this work, we have used an alternative strategy previously reported in the literature. [14,18] It is based on the analysis of the PC raw measurements, which allow www.advancedsciencenews.com www.pss-rapid.com to distinguish different trap species using the PC decay time constant rather than characterizing the trap properties.…”

“…There have been just a few works that reported on a beneficial effect regarding the suppression and/or reduction of trapping effects in multicrystalline (mc-Si) after physico-chemical treatments. For instance, S. Jafari et al 13 achieved a full removal of trapping effects in mc-Si by applying an infrarred laser treatment; however, the bulk lifetime values of treated wafers were also affected and considerably reduced due to a higher recombination rate. On the other hand, Macdonald et al 14 showed that PDG treatment can have a two-fold effect: an increase of the minority carrier lifetime and a moderate reduction of the trap concentration.…”

On the Correlation between Light-Induced Degradation and Minority Carrier Traps in Boron-Doped Czochralski Silicon

“…The signal disappeared from the DLTS spectra after the degradation process. 17 It was argued by the authors, and more recently in 19 , that a minority carrier trap (hereafter, a trap) is acting as a precursor for the recombination active BO defect. Furthermore, it has been suggested that in the degraded state the enhanced recombination occurs due to a shallow acceptor defect level through a trap-assisted Auger recombination process.…”