Electrical Measurement Techniques
| Non-contact Photo-voltage, Sheet Resistance measurements for Solar Cell, Photo-diode and LED/Laser diode applications |
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| Non-contact measurement of p-n junction photo-voltage, with analysis for junction sheet resistance. Optional measurements include minority carrier diffusion length. Available as fully automated (C2C), in-line monitoring on moving belt and compact bench top R&D version. |
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| Applications: The Rs Solar provides precision evaluation of the photo-response of surface junctions as well as fundamental electrical properties such as sheet resistance and minority carrier diffusion length. The tool is available in a number of forms, from single-point sample measurements to fully automated C2C and in line measurements |
| Sheet resistance Sheet resistance, Rs, measurements are provided with high precision (2% for Rs) over an Rs range from 10 – 500 Ohm/sq. Rs data are displayed with variety of map formats and line Scan. |
| Minority carrier lifetime (optional probe) An optional additional probe is available to provide surface photo-voltage (SPV) measurements of minority carrier diffusion length. |
| Principle of Measurement: The Rs Solar mapping tool uses junction photo-voltage (JPV) measurements to determine sheet resistance analysis of carrier spreading in surface p-n junctions. Electron-hole pairs are created by the absorbed photon energy in the illuminated region. The carrier diffusion and drift is monitored at the transparent (V1) and offset (V2) electrodes. By analysis of the electrode signals over a range of light signal modulation frequencies, the junction sheet resistance are determined from the photo-voltage signals. |
| Materials: P-N junctions in Si, Ge, SiGe alloy layers, III-V multi layers and others. |
| Throughput: C2C Semi Auto with mapping capability: 973 points in <3 min |