Towards realization of a large‐area light‐emitting diode‐based solar simulator

Abstract

Solar simulators based on light‐emitting diodes (LEDs) have shown great promise as alternative light sources for indoor testing of photovoltaic cells with certain characteristics that make them superior to the traditional solar simulators. 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 the form of a synthesized AM 1.5 spectrum over an area of 25 cm × 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 International Electrotechnical Commission standards on solar simulators for class rating. Although the light intensity with our current design and settings falls short of the standard 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. Copyright © 2011 John Wiley & Sons, Ltd.

Compact Light-Emitting Diode-Based AAA Class Solar Simulator: Design and Application Peculiarities

“…Another approach for LED-based solar simulators is to cover only visible part of spectrum with acceptable light intensity and nonuniformity [12], [13]. The secondary optics was applied to increase the power density and the uniformity of light flux to meet the requirement: An LED-based large area solar simulator with 5-m long mirror waveguides was presented in [14]. Currently, the light intensity insufficiency problem can already be solved due to recent advances in high-power visible and near-infrared LED technology.…”

Effective Low-Cost Hybrid LED-Halogen Solar Simulator

“…Another solution is proposed by the National Institute of Standards and Technology [9], where, with few monochromatic and white (5500 K), NIR, and ultraviolet (UV) LEDs, an approximation of the AM 1.5 sun spectrum in the wavelength interval from 400 to 970 nm was achieved. As the output optics were used, the 5-mlong light tapered guide allowed a relatively low nonuniformity: less than 10% for an illuminated area of 25 × 50 cm 2 .…”

Investigation of solar simulator based on high-power light-emitting diodes

“…AM1.5G spectral distribution reaching intensities up to 3 suns was approximated by independent tuning of 18 types of LEDs with different wavelengths in a still relatively complex array of 182 LED chips [7]. Recently, a large area solar simulator with 5-meter-long mirror waveguides and 34 types of different LEDs was presented [8]. A LED-based solar simulator prototype covering only a visible part of the spectrum with C-class uniformity on a 5 × 10 cm area was also demonstrated [9].…”

“…The aim of our work was to demonstrate that a compact array of only six types of LEDs (cool white, royal blue, deep red, far red, and two types of IR) can be sufficient for simulation of high (at least 100 mW/cm 2 , i. e. 1 sun) light flux density with A-class [2] spectral distribution match and A-class irradiance non-uniformity for the test area of at least several cm 2 . Reduction of the total number of LED chips from hundreds (used in [7]) to tens and absence of complex optics (used in [8]) were also set as additional criteria for the compactness of the system and the simplicity of its circuit design.…”