We have a new video featuring our Unisim Compact solar simulator which gives a guided tour of the system as well as some of the optional extras that can be fitted during manufacture.

The video also covers the concept of using the Unisim Compact solar simulator as a simplified 4-zone solar simulator. For more information on this, or how the LED boost zones work, see our technical note here.

Click the image opposite to see the video, or watch it on the Unisim Comact solar simulator product page.

TS-Space Systems is proud to have supplied a Unisim Solar Simulator to NEC Space Technologies, LTD. a world leader in the manufacture and testing of satellite equipment.

The Unisim close match solar simulator provides a world leading close spectral match to the standard AM0 spectrum via multiple discrete wavebands which is vital for accurately characterising the multijunction solar cells used for space applications.

"We are very pleased to work with NEC Space Technologies LTD again", said Dr Bill Williams, Director at TS-Space Systems, "We are proud to add NEC Space Technologies LTD. to the long list of leading PV research and manufacturing groups who have selected our solar simulators for their work".

The basic technique, assuming that illumination levels above and below AM0 are required, is to reduce the overall level of illumination of the simulator so as to be, say, 10% below AM0, but maintaining the AM0 spectral distribution (Figure 1).

Selected LED's are then used to provide the correct illumination for each junction at AM0 (Figure 2). By varying the output of these LED's, the current in any selected junction may be increased or decreased as required. In this way, any junction may be investigated independently of any other junction. Please note that alternative LED wavelengths to the ones demonstrated here are available.

At TS-Space Systems, when we made the worlds first multi-source close match solar simulator back in 1997 [2], we also made the world's first multi zone solar simulator by definition. What is a "zone" when it comes to solar simulators? It's a good question and one we get asked quite a lot of the time.

Modern multi-source solar simulators follow a general pattern of combining an arc lamp (traditionally Xenon) with one or more  incandescent lamps. At TS-Space Systems we've lead the way by adopting Metal Halide arc lamps for our latest range of solar simulators which are cheaper and much more stable than Xenon sources without using feedback controllers.

But where our solar simulators really excel is their division of the spectrum into independently controllable wavebands. We call these spectral "zones". As an example, the measured spectrum of a TS-Space Systems Unisim, quad-source (four zone) solar simulator is shown to the left.

The intensity of each "zone" can be adjusted independently in a TS-Space Systems Unisim solar simulator. Being able to adjust discrete portions of the spectrum while a device is under test allows for specific sub-cells to be limited or saturated with their appropriate wavelength of light. Thus the behaviour and characteristcs of the device can be fully investigated.

A further distincition can therefore be drawn between advanced solar simulators which provide a close-match and those which not only provide a close-match, but divide the spectrum into controllable "zones" which are suited to the spectral response of each band gap within the solar cell. 

What happens when you need more than four "zones"? That's where our Unisim N-Zone comes in.