Comparison of the radiation hardness of silicon based and perovskite based solar cells

Highly efficient perovskite based solar cells can in the near future be a valid alternative to conventional silicon based, but also to high efficiency triple junction IIII-V material based solar cells, because they are light weight, radiation tolerant and can be deposited on flexible, roll-able polymeric substrates. By irradiation of a variety of different solar cells with 68 MeV protons the radiation hardness of the different materials has been tested. At this high energy, protons are difficult to shield. Also the changing of the absorbance of transparent encapsulation material has to be taken into account. While in the case of the silicon based solar cells there is an inverse relation between the initial efficiency and the solar cell stability, in the case of perovskite this has not been found. Triple-Cation perovskite solar cells with more than 18% initial efficiency had a several orders of magnitude better stability than crystalline silicon based solar cells. For the latter devices it has been found that the initial higher efficiency of float-zone Silicon based solar cells as compared to Czrochralski silicon based solar cells gets suddenly lost with proton irradiation and for higher doses both types of solar cells degrade in a similar manner. Amorphous silicon based solar cells, with their initially much higher electronic defect density exhibit a much better stability under high energy particle irradiation, but their initial stability has an about 50% lower value as compared to the perovskite based solar cells. It should also be mentioned, that these two latter solar cell technologies after the end of the proton irradiation are showing a remarkable partial annealing of the radiation induced defects.