The solar spectrum describes the distribution of solar radiation energy across different wavelengths. Because sunlight changes as it passes through the Earth’s atmosphere, several reference spectra have been defined for scientific and industrial use.
Two of the most widely used reference spectra are AM1.5G and AM0.
AM1.5G (Air Mass 1.5 Global) represents the solar spectrum at the Earth’s surface under standard atmospheric conditions. It corresponds to sunlight passing through approximately 1.5 times the thickness of the Earth’s atmosphere and is widely used for photovoltaic device testing.
AM0 represents the solar spectrum outside the Earth’s atmosphere. This spectrum is commonly used for testing solar cells and materials intended for space applications.
Solar simulators reproduce these reference spectra using controlled light sources and optical filters, allowing laboratory experiments to be conducted under standardized sunlight conditions.