Highly efficient hole injection from Au electrode to fullerene-doped triphenylamine derivative layer

Abstract

Triphenylamine derivatives are superior hole-transport materials. For their application to high-functional organic semiconductor devices, efficient hole injection at the electrode/triphenylamine derivative interface is required. Herein, we report the design and evaluation of a Au/fullerene-doped α-phenyl-4′-[(4-methoxyphenyl)phenylamino]stilbene (TPA) buffer layer/TPA/Au layered device. It exhibits rectification conductivity, indicating that hole injection occurs more easily at the Au/fullerene-doped TPA interface than at the Au/TPA interface. The Richardson-Schottky analysis of the device reveals that the hole injection barrier (ΦB) at the Au/fullerene-doped TPA interface decreases to 0.021 eV upon using C70 as a dopant, and ΦB of Au/TPA is as large as 0.37 eV. The reduced ΦB of 0.021 eV satisfies the condition for ohmic contact at room temperature (ΦB$$\le $$ ≤ 0.025 eV). Notably, C70 doping has a higher barrier-reduction effect than C60 doping. Furthermore, a noteworthy hole-injection mechanism, in which the ion–dipole interaction between TPA and fullerenes plays an important role in reducing the barrier height, is considered based on cyclic voltammetry. These results should facilitate the design of an electrode/organic semiconductor interface for realizing low-voltage driven organic devices.

Morphology optimization of side-chain copolymers yields a ternary memory device with high stability and reproducibility

“…6b, the injection barrier from ITO to the HOMO of PMCz 1 - co -PMNCz 1 , PMCz 2 - co -PMNCz 1 and PMCz 4 - co -PMNCz 1 was much lower than that from Al to the LUMO of PMCz 1 - co -PMNCz 1 , PMCz 2 - co -PMNCz 1 and PMCz 4 - co -PMNCz 1 ; therefore, all these three polymers showed the p-type semiconductor characteristic, and the memory performance was dominated by hole injection. 32 Thus, under an external electric-field voltage around 1.10 V, the carbazole pendants near the ITO substrate would be oxidized first to form positively charged ions (Fig. 6c).…”

Electron-donating arene-substituted pentacenedione derivatives: a study of structural, electronic, and electrochemical properties

“…As for organic p-donors, numerous research efforts have been focused on the design and synthesis of triphenylamine (TPA) derivatives, since the physicochemical properties of this class of compounds can be exibly tuned through attachment of electron-donating or electron-accepting groups. [41][42][43][44] TPA derivatives have found applications as dye sensitizers in solar cells, 45 organic semiconductors, 46,47 electroluminophores in organic light-emitting diodes, 48 and superior photosensitizer. 49 Very recently, Sau and Samanta reported the synthesis of TPAanthraquinone-based D-A hypercrosslinked polymers via Suzuki-Miyaura cross-coupling reaction between tris(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)amine and 2,6dibromoanthracene-9,10-dione.…”