A Novel Solar Simulator Based on a Supercontinuum Laser for Solar Cell Device and Materials Characterization

The design, operation, and application of a novel solar simulator based on a high-power supercontinuum fiber laser are described. The simulator features a multisun irradiance with continuous spectral coverage from the visible to the infrared. By use of a prism-based spectral shaper, the simulator can be matched to any desired spectral profile, including the ASTM G-173-03 air-mass 1.5 reference spectrum. The simulator was used to measure the efficiency of gallium arsenide (GaAs), crystalline silicon (Si), amorphous Si, and copper-indium-gallium-selenide (CIGS) thin-film solar cells, showing agreement with independent measurements. The pulsed temporal characteristic of the simulator was studied and would appear to have a negligible influence on measured cell efficiency. The simulator light was focused to a spot of approximately 8 mu m in diameter and used to create micrometer-scale spatial maps of full spectrum optical-beam-induced current. Microscopic details such as grid lines, damage spots, and material variations were selectively excited and resolved on GaAs and CIGS cells. The spectral shaping capabilities were used to create output spectra appropriate for selectively light-biasing multijunction cell layers. The simulator was used to create variable blue-rich and red-rich spectra that were applied to a GaInP/GaAs tandem solar cell to illustrate the current-limiting behavior.