The production of silicon-based solar panel equipment using photovoltaic (PV) silicon material is upgraded to metallurgical grade with a purity of at least 6N. Quality control of the silicon refining process is essential to ensure high yield production.
Excellent detection limit
CAMECA Machine IMS 7f-Auto provides quantitative measurement of trace element impurity concentrations in PV silicon material with detection limits from ppm down to ppb, depending on the type to be analyzed.
The SIMS detection limits in silicon for 15ng of analyzed material are shown in the table below. The performance of the CAMECA IMS 7f-Auto is particularly attractive for analyzing light elements (H, C, O, N), the main impurities of silicon (B, P, As), as well as metals (Al, Cr, Fe, Ni, Cu, …). In contrast to TOF-SIMS, the detection limits of the IMS 7f-Auto improve with increased analysis speed.
| Species | atoms/cm3 | ppb |
| H | 7E+16 | 1400 |
| B | 1E+13 | 0.2 |
| C | 2E+16 | 400 |
| O | 2E+16 | 400 |
| Na | 3E+13 | 0.6 |
| Al | 1E+13 | 0.2 |
| P | 5E+13 | 1 |
| K | 2E+12 | 0.04 |
| Ca | 7E+11 | 0.01 |
| Cr | 5E+12 | 0.1 |
| Mn | 5E+12 | 0.1 |
| Iron | 2E+14 | 4 |
| Company | 2E+13 | 0.4 |
| Ni | 6E+14 | 12 |
| Copper | 2E+14 | 4 |
| EQUAL TO | 2E+13 | 0.2 |
| Mo | 1E+14 | 2 |
| West | 5E+13 | 1 |
The lowest detection limit achieved for light elements, thanks to ultra-high vacuum conditions optimized by combining the titanium sublimation process with a turbomolecular pump in the analysis chamber. The chart on the front page illustrates the excellent detection limit for oxygen in silicon. PV Si can be analyzed.
With high sample throughput in the initial physical form and a quick and easy sample preparation process on the IMS 7f-Auto. The typical throughput is 4-6 analyses per hour. The device can be equipped with an automatic storage chamber with up to 6 sample holders, thus ensuring even higher throughput.
For more details, you can request the publication: SIMS Analytical Techniques for PV Applications. P. Peres et al. Surface and Interface Analysis, n/a. doi: 10.1002/sia.3525. This paper presents the analytical performance provided by SIMS tools for the development and production of new photovoltaic cells with results for two main applications: trace element analysis in PV Si materials, depth distribution of major components and trace elements in CIGS thin films.