Introduction
Nanocrystal based solar cells have been demonstrated as
a possible next generation lower-cost alternative to traditional
silicon based solar cells.1 Towards this end, the formation of
inexpensive, earth-abundant nanomaterials for renewable energy
is crucial to their potential utilization in large-scale solar cell
applications.2 One such material candidate is cuprous sulfide
(Cu2S), a naturally occurring abundant mineral with a bandgap
of about 1.2 eV.3 Small variations in the electronic band structure
arise depending on the crystal phase and stoichiometry. Based
upon its elemental composition, Cu2S offers a benign environmental
profile when compared to its cadmium or lead based
nanomaterial counterparts. This combination of properties
positions Cu2S as a leading material candidate for future solar
applications.