For the first time, we have fabricated nanotube
CdS-CdTe solar cells with a PCE in excess of 10%.
The efficiency could be further improved through the
improvement of Voc and the fill factor, by reducing
the densities of the traps and interface states through
optimizing the growth of CdS nanotubes and CdTe,
developing low-resistance back contacts, and developing
a better understanding of nanotube junctions
and interfaces.