Optimizing the Spatial Nonuniformity of Irradiance in a Large-Area LED Solar Simulator

Abstract

The solar simulator has allowed all photovoltaic devices to be developed and tested under laboratory conditions. Filtered xenon arc lamps were the gold-standard source for solar simulation of small-area silicon photovoltaic devices; however, scaling these devices to illuminate large areas is neither efficient nor practical. Large-area solar simulation to meet appropriate spectral content and spatial nonuniformity of irradiance (SNI) standards has traditionally been difficult and expensive to achieve, partly due to the light sources employed. LED-based solar simulation allows a better electrical efficiency and uniformity of irradiance while meeting spectral intensity requirements with better form factors. This work details the design based on optical modeling of a scalable, large-area, LED-based, solar simulator meeting Class AAA performance standards formed for inline testing of printed solar cells. The modular design approach employed enables the illuminated area to be expanded in quanta of ~260 cm2 to any preferred illumination area. A 640 cm2 area illuminated by two adjacent PCB units has a measured total emission of 100 mW/cm2, with a SNI of 1.7% and an excellent approximation to the AM1.5G spectrum over the wavelength range of 350–1100 nm. The measured long-term temporal instability of irradiance (TIE) is <0.5% for a 550-min continuous run. This work identifies the design steps and details the development and measurement of a scalable large-area LED-based solar simulator of interest to the PV testing community, and others using solar simulators.

Improved spectral mismatch and performance of a phosphor-converted light-emitting diode solar simulator

“…As a result, SM of the proposed SPD in the range of 400 to 500 nm and 700 to 800 nm closed to 1.00 and accorded to research objectives. The SM results were compared with the results by Al-Ahmad et al [16], [17], Sun et al [18], López-Fraguas et al [19] and Tavakoli et al [20]. They were in the A class as well but they used a lot of LEDs in the 400 to 700 nm range, and 7 to 11 types while the proposed system used only two types of LEDs (pc-nWLED+LED 420 nm).…”

“…The details were presented in Table 4. The LSS light sources using COB LEDs or COB mixed with high-power LEDs [2]- [4], [28] tend to produce higher LTI/STI than using high-power LEDs or surface mounted device (SMD) LEDs [1], [14], [16], [19]. This is because COB is a multi-chip structure with relatively high current density resulting in higher operating temperatures than high-power or SMD LEDs.…”

“…Subsequently, the solar simulator is developed to have a VIS spectrum that mimics more AM1.5G spectrum, so more spectra were added to that range. Al-Ahmad et al [16], [17] presented the 7 VIS spectra. Sun et al [18] reported the 10 VIS spectra.…”

Optimization of LED-Based Solar Simulators for Cadmium Telluride and Microcrystalline Silicon Solar Cells

“…Recently, such scalable simulators were demonstrated with hexagonal [8] and rectangular [9] layouts. Hexagonal LED patterns and a rectangular shape of the illuminated area can also be obtained simultaneously by tessellation of rectangular printed circuit boards [10].…”

“…Previously, it was also demonstrated how spectrum extension into the UV and IR ranges can be employed for efficient spectral characterization of solar cells and modules in order to reveal additional information about the properties of materials and the operation of solar cells [24]. The new version of the standard is referenced in [25,26] , where a AAA-class solar simulator for a large illuminated area of 640 cm 2 and a low-cost solar simulator for a 70 cm 2 area were demonstrated. A large illuminated area of 52 cm × 52 cm was also achieved with an ABA-class solar simulator in [27] based on a previous version of the standard.…”