In a previous work, BSFR type silicon solar cells designed for space applications have been electrically tested
under forward and reverse bias in a large temperature range (-30°C to 150°C), and their thermal behaviour
simultaneously observed by infrared thermography.
This study was done in order to know the highest reverse voltage a cell can be biased to, without damage
caused by breakdown, and to follow the evolution of cell temperature during the breakdown development.
In the present work, more realistic conditions of operation in space are imposed to a cell assembly bonded on a
test sample representative of a solar generator structure, hung in a vacuum chamber (1 06 torr) equipped with
a cryogenic wall and illuminated by an AMO 1 ,4 kW/m2 solar simulator through a window.
Thermal analysis of the test sample is achieved using thermocouples and an infrared long wave camera viewing
through a ZnSe window 45° tilted by reference to illumination axis.
Partial shadowing of the solar cells can be introduced to simulate perturbations by antennas or other arms of the
satellite. This cell shadowing can involve reverse biasing of a cell in a series assembly and cause local heating
(hot spot) of the cell.
Experiments have been conducted on two test samples, the first one equipped with two 20 mm x 40 mm BSFR
cells, the second one, with nine cells of the same type. Results of this last experiment are presented, with
attention paid to temperature measurements by IR thermography and thermal behaviour simulation of the