Technique for Measurement of semiconductor charge carrier density in the dark and irradiated using an LED lamp for photovoltaic purposes

The operation of solar cells is based on the photoconductive properties of semiconductor materials such as silicon, where the charge carriers, composed of electrons and holes, are fundamental for electrical generation. This study aims to apply a technique to measure the charge carrier density in a P-type silicon wafer of a thickness of 525 μm. Measurements were carried out under dark and irradiated conditions using a 12V LED lamp providing an irradiance of 18.1 W/m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. The lamp was characterized using a USB2000+ spectrometer according to ASTM E-927-10 standard, obtaining a CAC rating. A Faraday cage was constructed for the measurements, and an SPCB-01 system connected to a KEITHLEY 2450 source, which injected currents from -100 μA to 100 μA, was used. The measurements were performed inside a magnetic field of 150 mT. Preliminary results showed an average positive Hall voltage of 80 μV, indicating increased positive carriers. The carrier density under dark conditions was 4.11×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup>, while upon irradiation, it increased to 6.43×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup>, representing an increase of 56.4%.