Multi‐Spectrum Method for the Determination of the Spectral Responsivity and the Short‐Circuit Current of Photovoltaic Devices

Abstract

Herein, a method for the determination of the spectral responsivity (SR) and the short‐circuit current under standard test conditions of photovoltaic devices (e.g., solar cells) is presented. This multi‐spectrum SR method requires a spectrally tunable broadband light source irradiating the photovoltaic device with a large number of different spectra. For each spectrum, the light response of the device and the spectral irradiance in the measuring plane are measured. The spectral irradiances are integrated within predefined wavelength intervals and are incorporated together with the measured light response into an equation system which relates them to the (unknown) SR of the photovoltaic device. By solving the equation system, mathematically using regression algorithms, the SR is determined. Due to the usage of a broadband light source, the device operates at realistic injection conditions during measurements. The mathematical background of the multi‐spectrum SR method is described and its applicability is demonstrated on three world‐photovoltaic‐scale‐type solar cells and one large‐area reference cell. Short‐circuit currents from all SR curves are calculated using the tabulated AM1.5 G spectrum. In comparison to the SR reference data, the short‐circuit currents from the multi‐spectrum SR method deviate by less than 0.68%.