Enhanced Cu2S/CdS Coaxial Nanowire Solar Cells by Piezo-Phototronic Effect

Searching for renewable and green energy is one of the most urgent challenges to the sustainable development of human civilization owing to the threat of global warming and energy crises. Solar is probably the most abundant clean and renewable energy. Semiconductor nanowires (NWs) have a lot of advantages as candidates for photovoltaic (PV) applications(1) due to their large surface-to-volume ratio, better charge collection(2) and the possibility of enhanced absorption through light trapping(3, 4); at the other side, nanowires will cause large surface and interface recombination, which could be overcome by surface passivation(5) and epitaxial growth of p-n junctions(6). The core-shell geometry of NWs is proposed to be able to enhance the efficiency of charge collection by shortening the paths travelled by minority carriers(5-7), increasing the optical quality of the material(8), or strain engineering of the bandgap(8).