Ultrathin interlayers of a conjugated polyelectrolyte for low work-function cathodes in efficient inverted organic solar cells

作者：Zilberberg Kirill; Behrendt Andreas; Kraft Mario; Scherf Ullrich; Riedl Thomas^*

来源：Organic Electronics, 2013, 14(3): 951-957.

DOI：10.1016/j.orgel.2013.01.018

• Inverted organic solar cell
• Conjugated polyelectrolyte
• Low work-function cathode

Inverted polymer: fullerene solar cells are reported using the conjugated polyelectrolyte poly(3-[6-(N-methylimidazolium)hexyl]thiophene) bromide P3ImHT as ultra-thin cathode interlayer to reduce the work-WF) of ITO for improved electron selectivity. Similar to ITO/TiOx cathodes, UV exposure is found necessary in the case of ITO/CPE to achieve a high fill factor on the order of 60%. UV illumination is shown to lead to a reduction of the ITO WF which in combination with WF lowering due to the dipole of the CPE leads to a suitable electron selective cathode. As a result, inverted solar cells with an efficiency of 4.8% are achieved. This is the highest efficiency of an inverted OSC using a conjugated polyelectrolyte as interface modifier directly on top of ITO.

• 出版日期2013-3