Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.org/10.1002/anie.201902785. Scheme 1. Homogeneous versus semi-heterogeneous dual Ni/photocatalysis. Angewandte Chemie Communications Angewandte Chemie Communications 9577 Angew.C hem. Int.E d. 2019, 58,9 575 -9580

Brilliance usually refers to the light reflected by the facets of a gemstone such as diamond due to its high refractive index. Nowadays, high‐refractive‐index materials find application in many optical and photonic devices and are mostly of inorganic nature. However, these materials are usually obtained by toxic or expensive production processes. Herein, the synthesis of a thin‐film organic semiconductor, namely, polymeric carbon nitride, by thermal chemical vapor deposition is presented. Among polymers, this organic material combines the highest intrinsic refractive index reported so far with high transparency in the visible spectrum, even reaching the range of diamond. Eventually, the herein presented deposition of high quality thin films and their optical characteristics open the way for numerous new applications and devices in optics, photonics, and beyond based on organic materials.

Approaches to boost the efficiency and stability of perovskite solar cells often address one singular problem in a specific device configuration. In this work, we utilize a poly(ionic-liquid) (PIL) to...

Covalent modification of phenyl-modified carbon nitride with vinylthiazole groups via visible light induced grafting is reported. Modified structures express negative charge migration to the thiazole edges while the carbon nitride sheet remains positively charged in organic solutions. Such a phenomenon provides electrostatic stabilization of modified carbon nitride particles in organic media leading to highly organodispersible and colloidally stable carbon nitrides. The resulting structures can be homogeneously dispersed in organic solvents and can be cast to transparent films. The usefulness of such a processable colloidal carbon nitride building block is exemplified here by its high luminescence and inkjet printing of films.

Effective, solution-processable designs of interfacial electron-transporting layers (ETLs) or hole-blocking layers are promising tools in modern electronic devices, e.g., to improve the performance, cost, and stability of perovskite-based solar cells. Herein, we introduce a facile synthetic route of thiazole-modified carbon nitride with 1.5 nm thick nanosheets which can be processed to a homogeneous, metal-free ETL for inverted perovskite solar cells. We show that thiazole-modified carbon nitride enables electronic interface enhancement via suppression of charge recombination, achieving 1.09 V in V oc and a rise to 20.17 mA/cm2 in J sc. Hence, this report presents the successful implementation of a carbon-nitride-based structure to boost charge extraction from the perovskite absorber toward the electron transport layer in p-i-n devices.