Layout of a CIGS-based hybrid solar cell and its schematic energy level diagram. (a) Layout of the CIGS-based hybrid solar cell with the structure of ITO/CIGS/P3HT:PCBM/Al. (b) Schematic energy level diagram for the above structure (with energy levels in electron voltage relative to vacuum).
Zhao et al. Nanoscale Research Letters 2014 9:308 doi:10.1186/1556-276X-9-308