UV‐Induced Modification of Conjugated Polymers Using Gaseous Organosilanes

Abstract

AbstractSummary: This paper describes the use of trialkylsilanes for photoinduced patterning of electroluminescent polymers as a new field of application for this type of organosilicon compounds. Under UV irradiation, trialkylsilanes selectively saturate the vinylene groups in poly(p‐phenylenevinylene) (PPV)‐type polymers, while leaving aromatic units virtually unaffected (selective photobleaching). Spin cast films of polymer blends consisting of two or three different conjugated polymers were UV irradiated in the presence of gaseous trialkylsilane reagents (trimethylsilane and ethyldimethylsilane) to achieve multicolor patterning. Exploiting the host‐guest concept with polyfluorene (PF) derivatives as totally aromatic host matrix and PPV derivatives as guest polymers, dual‐color displays and, with constraints, three‐color LED displays were realized. Compared to previously reported reagents such as hydrazine and thiols, trialkylsilanes enable photochemical patterning under non‐toxic and odorless conditions. Possible mechanisms for the photoreaction with trialkylsilanes as well as perspectives for applications are discussed.Electroluminescence spectra of LEDs based on the host‐guest system.magnified imageElectroluminescence spectra of LEDs based on the host‐guest system.