- Tytuł:
- Optimized Temperature in Phosphorous Diffusion Gettering Setup of Chromium Transition Metal in Solar Grade Multicrystalline p-Type Silicon Wafer
- Autorzy:
-
Bouhafs, D.
Khelifati, N.
Kouhlane, Y. - Powiązania:
- https://bibliotekanauki.pl/articles/1398753.pdf
- Data publikacji:
- 2016-04
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
88.40.jj
81.05.Bx
81.65.Tx
87.15.Pc - Opis:
- We have investigated in this work the effect of the temperature profile during homogeneous phosphorous diffusion gettering (PDG) on multicrystalline (mc-Si) silicon p-type wafers destined for photovoltaic solar cells. Temperatures were varied from 800°C to 950°C with time cycle of 90 minutes. Phosphorous profile of n⁺p junction was measured by secondary ion mass spectroscopy (SIMS) from 0.45 μm to 2.4 μm. Chromium concentration profile measured on the same samples by SIMS shows a high accumulated concentration of Cr atoms in the gettering layer at 900°C and 950°C, compared to samples obtained at 800°C and 850°C. The effective lifetime $(\tau_\text{eff})$ of minority charge carriers characterized by quasi-steady state photoconductance (QSSPC) is in correlation with these results. From the QSSPC measurements we have observed an amelioration of $\tau_\text{eff}$ from 7 μs before PDG to 26 μs in the samples after PDG, processed at 900°C. This indicates the extraction of a non-negligible concentration (5×10¹⁴ cm¯³ to 5×10¹⁵ cm¯³) of Cr from the bulk to the surface gettering layer, as observed in the chromium SIMS profiles. A light degradation of $\tau_\text{eff}$ (18 μs) is observed in the samples treated at 950°C due probably to a partial dissolution of the metallic precipitates, especially at the grain boundaries and in the dislocations vicinity. The related $\tau_\text{Cr-Impurity}$ lifetime value of about 8.5 μs is extracted, which is the result of interstitial $Cr_{i}$ or $Cr_{i}B_{s}$ pairs, proving their strongest recombination activity in silicon.
- Źródło:
-
Acta Physica Polonica A; 2016, 129, 4; 690-693
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
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