Experimental study on optical characterization of mono crystalline silicon solar cell

Abstract

The experimental works have been done on the optical characterization of mono crystalline solar cell by Surface Photo Voltage (SPV) measurement for fabricated solar cell by observing minority carrier diffusion length (L) & life time (τ). The core objective of this research was to reduce the cost of solar cell and increase the efficiency by analysis the optical characterization. As the PV cell is one kind of photo diode so the surface photo voltage is very important part of characterization of cell fabrication. There is a direct relation between the minority carrier lifetime and solar cell efficiency. The method of SPV is a contactless system that helps to analysis the optical characterization of semiconductors. It measures the diffusion length of minority carriers in the region of essential light absorption inside solar cells and wafers. The minority carrier diffusion length, L is an important factor for cell efficiency and spectral response of the mono crystalline silicon solar cell. It is also necessary for evaluation of the p-type silicon wafer. In this experiment the surface photo voltage (SPV) of fabricated solar cells have been analyzed and observed minority carrier flow by Light Current Voltage (LIV) tester as it represented the quality of fabrication process and efficiency of the solar cell. A simple computer-controlled, normal incidence measurement system was designed for SPV measurements of minority carrier diffusion length and lifetime of Si-solar cell. Measurement system is based on a mini monochromator driven with a steeper motor to vary wavelengths in 400-1200 nm spectral range . Light induced surface photo voltage is measured as a function of the wavelength. SPV is measured using a Standard Research 510 lock in amplifier. A LabVIEW interface is used for system control and data acquisition. After calculating the experimental data obtained from mono crystalline silicon solar cells measurement, minority carrier diffusion length and life time were calculated and it was 92 μm and almost 3.135 μs respectively. By using solar simulator‘s (Sun Simulator K3000 LAB55) platform at 25oC efficiency was measured and it was 16.04%.