Pyrite as promising monograin layer solar cell absorber material for in-situ solar cell fabrication on the Moon

Reliable energy sources are needed in order to keep a Lunar Base on the run, and solar energy is one of the most attractive options. There are two ways to achieve it - to bring necessary solar panels from the Earth or find a way to produce them in-situ on the Moon from local resources. We propose the monograin layer (MGL) solar cell technology, that could be used for the in-situ production of solar panels on the Moon. One of the most promising compounds, that can be used as an absorber material in a monograin layer solar cell is pyrite FeS2. There are considerable amounts of iron and sulphur in the lunar regolith. Conditions for the synthesis-growth of FeS2 monograin powders were found and are presented in this study. The synthesis-growth of FeS2 powder at 740 degrees C in potassium iodide for one week followed by slow cooling to 575 degrees C and rapid cooling to the room temperature, resulted in single phase pyrite monograin powder. Powder crystals had round shape and the median size of about 50 mu m was appropriate for making monograin layers. The produced FeS2 MGLs were used as absorber layers in MGL solar cells with structure as graphite/FeS2/NiO/TCO and in FeS2/Pt Schottky diodes. Charge carrier concentration of 6.2 x 10(16) cm(-3) was determined from capacitance-voltage measurements of FeS2/NiO heterostructure and 2.5 x 10(17) cm(-3) from FeS2/Pt Schottky diode.

Automated summary

This study proposes the use of monograin layer (MGL) solar cell technology for in-situ production of solar panels on the Moon. The synthesis-growth of suitable single phase pyrite monograin powder from local resources was achieved. The produced FeS2 MGLs were used as absorber layers in MGL solar cells.