Over 19% Efficiency in Ternary Organic Solar Cells Enabled by n‑Type Dopants

Zhaoheng Ling, Mohamad Insan Nugraha, Wisnu Tantyo Hadmojo, Yuanbao Lin, Sang Young Jeong, Emre Yengel, Hendrik Faber, Hua Tang, Frédéric Laquai, Abdul-Hamid Emwas, Xiaoming Chang, Temur Maksudov, Murali Gedda, Han Young Woo, Iain McCulloch, Martin Heeney, Leonidas Tsetseris, and Thomas D. Anthopoulos

ACS Energy Letters 2023 8 (10), 4104-4112

DOI: 10.1021/acsenergylett.3c01254

This study explores the use of ethyl viologen (EV) and methyl viologen (MV) as n-type dopants in organic photovoltaics (OPVs). Incorporating these dopants into a ternary blend significantly improves OPV performance, with PCEs up to 19.03%. EV and MV enhance microstructure and absorption, balance carrier mobility, and reduce recombination, offering a promising route for advanced OPV efficiency.

How Paios Was used

In the study, Paios from Fluxim was employed for various measurements in both steady-state and transient modes. Specifically, it was used for Transient Photo-Voltage (TPV) measurements to observe photovoltage decay under small optical perturbations and various light-intensity biases. This helped in analyzing bimolecular charge carrier recombination. Additionally, Photo-CELIV measurements and Electrochemical Impedance Spectroscopy (EIS) were conducted using PAIOS, the latter under an open circuit voltage in the dark across a frequency range of 3 MHz to 300 Hz​