Redox-active organometallic dimers as dopants and surface modifiers in optoelectronics

Doping;Semiconductors;Perovskite solar cells;Surface modification;Interface engineering

Pulvirenti, Federico ; Marder, Seth Richard Chemistry and Biochemistry Silva Acuña, Carlos Reichmanis, Elsa Brédas, Jean-Luc Kippelen, Bernard ; Marder, Seth Richard

University:Georgia Institute of Technology

Department:Chemistry and Biochemistry

关键词: Doping;    Semiconductors;    Perovskite solar cells;    Surface modification;    Interface engineering;   

Others  :  https://smartech.gatech.edu/bitstream/1853/62678/1/PULVIRENTI-DISSERTATION-2019.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

This dissertation focuses on the use of the dimers formed by some 19-electron organometallic sandwich compounds to tune the electronic properties of transparent conductive oxides, particularly indium tin oxide (ITO) and fluorinated tin oxide (FTO), and organic electron-transporting materials (ETMs), specifically fullerene and perylene diimide derivatives used in perovskite solar cells (PSCs). The dimers reduce the work function (WF) of electrode materials by transferring electrons to the metal oxides, forming metal-organic monomeric cations electrostatically bound to the reduced electrode, or n-dope ETMs through a similar reaction. This dissertation is an investigation of the relationship between the processing method by which dimers are deposited on metal oxides or along with organic semiconductors, their ability to lower the WF of the electrode and/or to increase the electrical conductivity of ETMs, their chemical state in these doped materials, and the electrical behavior of the modified substrate in simple and complex optoelectronic devices. Moreover, the stability of the WF modification to solvent washing, temperature and processing route of ETM overlayers is explored. Two strategies to prevent washing of monomer cations and their diffusion are proposed: one entailing the combination of phosphonic acid and organometallic dimer modification of metal oxides; one entailing the use of a crosslinker in bulk-doped fullerene derivatives. The effect of the choice of surface-modification layer and ETM on charge collection in PSCs is assessed. The findings of this dissertation will contribute to the development of robust surface modification and doping approaches for the fabrication of efficient and stable optoelectronic devices.