Tris(2-(1H-pyrazol-1-yl)pyridine)cobalt(III) as p-Type Dopant for Organic Semiconductors and Its Application in Highly Efficient Solid-State Dye-Sensitized Solar Cells

Abstract

Chemical doping is an important strategy to alter the charge-transport properties of both molecular and polymeric organic semiconductors that find widespread application in organic electronic devices. We report on the use of a new class of Co(III) complexes as p-type dopants for triarylamine-based hole conductors such as spiro-MeOTAD and their application in solid-state dye-sensitized solar cells (ssDSCs). We show that the proposed compounds fulfill the requirements for this application and that the discussed strategy is promising for tuning the conductivity of spiro-MeOTAD in ssDSCs, without having to rely on the commonly employed photo-doping. By using a recently developed high molar extinction coefficient organic D-π-A sensitizer and p-doped spiro-MeOTAD as hole conductor, we achieved a record power conversion efficiency of 7.2%, measured under standard solar conditions (AM1.5G, 100 mW cm(-2)). We expect these promising new dopants to find widespread applications in organic electronics in general and photovoltaics in particular.

High Performance Perovskite Solar Cells

“…However, spiro‐MeOTAD suffers from low hole mobility and conductivity,43 owing to its pristine, unique structure. Additives, such as Li‐bis(trifluoromethanesulfonyl) imide (Li‐TFSI), perfluoro‐tetracyanoquino‐dime thane (F4TCNQ) and tris(2‐(1H‐ pyrazol‐1‐yl) pyridine) cobalt(III) (FK102 Co(III)) are necessary to dope and improve conductivity of spiro‐MeOTAD,43, 44 rendering high‐cost and complex synthesis in corresponding perovskite solar cell fabrication.…”

Efficient and stable CH3NH3PbI3-sensitized ZnO nanorod array solid-state solar cells

“…5 To date, the efficiency of solid-state DSCs (ssDSCs) is still lower than the conventional DSCs based on a liquid electrolyte. 6 Generally, the lower performance of ssDSCs is attributed to incomplete pore-lling of the mesoporous TiO 2 with the solid hole transporting material (HTM) and to limited light harvesting because of the use of relatively thin mesoporous TiO 2 lms. 7,8 One approach to improve the lling sensitized lms with solid HTMs is to replace the nanoparticles in the mesoporous lm with vertically ordered (1D) nanostructures, providing a direct pathway for electron transport and a straight channel for lling the pores of the sensitized lm with the HTM solution.…”

New generation solar cells: concepts, trends and perspectives

“…13) in organic-based materials, giving an overall efficiency of 7.2% when paired with Y123 dye (Fig. 13), 112 and CsSnI 3 in the inorganic analogues, reaching 10.2% in conjunction with N719 dye (Fig. 10).…”