LED-based solar simulators have shown great promise as alternative light sources for indoor testing of PV cells as compared to their traditional counterparts. However, large-area uniform illumination more suitable for larger cells and module measurements still remain a challenge today. In this paper, we discuss the development and fabrication of a scalable large-area LED-based solar simulator that consists of multiple tapered light guides. We demonstrate fine intermixing of many LED light rays and power delivery in form of a synthesized air mass (AM) 1.5 spectrum over an area of 25 cm by 50 cm with better than 10 % spatial nonuniformity. We present the spectral output, the spatial uniformity and the temporal stability of the simulator in both the constant current mode and the pulsed-mode LED operation, and compare our data with the IEC standards on solar simulators for class rating. Although the light intensity with our current design and settings falls short of the solar AM 1.5 intensity, this design and further improvements open up the possibility of achieving large-area, high-power indoor solar simulation with various desired spectra.
Citation: Progress in Photovoltaics
Pub Type: Journals
Photovoltaics, PV, Solar Cell, Simulator, Indoor, LED, uniformity, large area