ESA led solar cell R&D is extending the reach of solar-powered spacecraft across the solar system, including Bepi-Colombo to Mercury (seen here).
Operating solar cells close to the Sun actually presents a tall order, as cell efficiency decreases as temperature increases. Venus Express needs to endure spacecraft heating four times higher than normal, while BepiColombo will have to cope with solar radiation ten times more intense than that of Earth orbit, and to temperatures of about 350°C – 120 degrees higher than the maximum tolerable solar cell operating temperature. The Agency's Solar Orbiter probe will fly even closer, experiencing sunlight 22 times brighter than in Earth orbit.
For missions headed in the other direction, out to deep space, low-intensity low-temperature (LILT) solar cells have been tailored, enabling missions all the out out to Jupiter.
These new types of solar cells also have potential applications on Earth - LILT cells have been adapted for smart hotel keys, capable of running on indoor light levels alone.