Effects of Beam Conditions in Ground Irradiation Tests on Degradation of Photovoltaic Characteristics of Space Solar Cells

Abstract

We investigated the effects of irradiation beam conditions on the performance degradation of silicon and triple-junction solar cells for use in space. The fluence rates of electron and proton beams were varied. Degradation did not depend on the fluence rate of protons for both cells. A higher fluence rate of electrons caused greater degradation of the Si cell, but the dependence was due to the temperature increase during irradiation. Two beam-area expansion methods, defocusing and scanning, were examined for proton irradiation of various energies (50 keV–10 MeV). In comparing the output degradation from irradiation with defocused and scanned proton beams, no significant difference in degradation was found for any proton energy. We plan to reflect these findings into ISO standard of irradiation test method of space solar cells.

Ion Accelerator Facility of the Wakasa Wan Energy Research Center for the Study of Irradiation Effects on Space Electronics

“…They have found that the photovoltaic properties of both the solar cells are degraded irrespective of the fluence rate or the irradiation mode. The details are discussed in [25].…”

“…Using these accelerators, we have been involved in research on the destruction of tumor cells in human bodies (proton beam radiotherapy) [3,4], the transmutation of DNAs in plants and bacteria (ion beam breeding) [5][6][7], ion beam material modification [8][9][10] and ion beam analysis for materials [11][12][13]. The accelerators at WERC have also been utilized to simulate the radiation effects on materials which are related to nuclear power plants [14][15][16] and those of space electronics [17][18][19][20][21][22][23][24][25]. Electronic systems are severely affected by the radiation environment in space.…”

Displacement damage dose analysis of the output characteristics of In0.5Ga0.5P and Cu(In,Ga)(S,Se)2 solar cells irradiated with alpha ray simulated helium ions

“…Note that in the cases of proton and He + -ion irradiations, it is confirmed that the sample temperature does not change, while a water-cooled sample plate was used in the case of the electron irradiation. 18) Thus, the sample temperature was kept at room temperature (ambient) during all the irradiations.…”