Substrate configuration, bifacial CdTe solar cells grown directly on transparent single wall carbon nanotube back contacts

Substrate configuration CdTe/CdS solar cells were fabricated directly on 25 nm thick single wall carbon nanotube (SWCNT) back contacts using a high temperature, commercial deposition process. No copper was introduced to facilitate the formation of an ohmic back contact at the back of the device. The champion device had an efficiency of 6.5%. The thin SWCNT layer allowed the device to be illuminated through the back contact, and a comparison of the device performance with front and backside illumination revealed several novel features of the SWCNT back contact. Our findings indicate that SWCNT films may be useful as a recombination layer contact for bifacial solar cells, photovoltaic windows, or two-terminal thin-film tandem solar cells. (C) 2016 Elsevier B.V. All rights reserved.