SILICON SOLAR CELL AS SENSOR FOR SOLAR GLOBAL RADIATION MEASUREMENTS

Abstract

In this work were developed radiometers for global radiation measurements having conventional monocrystaline silicon solar cells as se nsor. The solar cell was developed using silicon slices growth by CZ, type-p, (100), with resistivity of 1 Ω.cm, area of 15 x 15mm and antireflective coating of TiO2. This solar cell presents open circuit voltage of 580 mV, short circuit current of 70 mA, maximum power out put of 28mW and 12% of efficiency measured under AM1.5 spectrum, temperature of 25C. The solar cells are located in a cylindrical container of cast aluminum. This container is fixed on a base where there is a level indicator for cell positioning. Under cell there is an optical window for cosine law compatibility. The solar cell and electric circuit are protected against humidity. For radiometers calibration were set up systems for absolute calibration, spectral response and cosine law. The engineering model was tested against humidity, ultraviolet radiation and salt spray. The radiometer was also tested in a data collect station in the Centro de Previsão do Tempo e Estudos Climáticos – CPTEC at INPE in Cachoeira Paulista-SP.