Behavior of silicon bypass diodes in proton and high temperature environments for Mercury probe MMO

The behavior of silicon bypass diodes for space solar cells was experimentally investigated at high temperatures up to 250 °C for the design of Japan's Mercury probe BepiColombo MMO. Though the reverse current increased to nearly 10 mA at 250 °C, the operation at such high temperatures did not permanently damaged the diodes. When the diodes were irradiated with protons and then kept at high temperatures, the output power recovered by annealing. The recovery was faster if the diodes were forward biased, presumably because of minority-carrier-injection-enhanced-annealing.