Organic materials containing heavy atoms have been used in photovoltaics to overcome a fundamental limitation: short exciton diffusion length (LD). We highlight studies showing increased LD in solar cells using triplet-generating materials and tackle challenges that the field faces with possible avenues for future research.

The discovery of metallic conductivity in polyacetylene [‐HC=CH‐]n upon doping represents a landmark achievement. However, the insolubility of polyacetylene and a dearth of methods for its chemical modification have limited its widespread use. Here, we employ a ring‐opening metathesis polymerization (ROMP) protocol to prepare functionalized polyacetylenes (fPAs) bearing: (1) electron‐deficient boryl (‐BR2) and phosphoryl (‐P(O)R2) side chains; (2) electron‐donating amino (‐NR2) groups, and (3) ring‐fused 1,2,3‐triazolium units via strain‐promoted Click chemistry. These functional groups render most of the fPAs soluble and can lead to intense light absorption across the visible to near‐IR region. Also, the presence of redox‐active boryl and amino groups leads to opposing near‐IR optical responses upon (electro)chemical reduction or oxidation. Some of the resulting fPAs show greatly enhanced air stability when compared to known polyacetylenes. Lastly, these fPAs can be cross‐linked to yield network materials with the full retention of optical properties.

Luminescent silicon nanoparticles have been widely recognized as an alternative for metal-based quantum dots (QDs) for optoelectronics partly because of the high abundance and biocompatibility of silicon. To date, the broad photoluminescence line width (often >100 nm) of silicon QDs has been a hurdle to achieving competitive spectral purity and incorporating them into lightemitting devices. Herein we report fabrication and testing of straightforward configuration of Fabry−Peŕot resonators that incorporates a thin layer of SiQD− polymer hybrid/blend between two reflective silver mirrors; remarkably these devices exhibit up-to-14-fold narrowing of SiQD emission and achieve a spectral bandwidth as narrow as ca. 9 nm. Our polymer-based, SiQD-containing Fabry− Peŕot resonators also provide convenient spectral tunability, can be prepared using a variety of polymer hosts and substrates, and enable rigid as well as flexible devices.

New poly- and oligotellurophenes bearing cycloalkyl and 3-aryl substituents have been reported, with narrow band gaps approaching 1.3 eV observed.

Donor–acceptor materials containing tris(triazolo)triazine (TTT) acceptors have recently gained attention as green to deep-blue fluorophores exhibiting thermally activated delayed fluorescence (TADF).

The discovery of metallic conductivity in polyacetylene [‐HC=CH‐]n upon doping represents a landmark achievement. However, the insolubility of polyacetylene and a dearth of methods for its chemical modification have limited its widespread use. Here, we employ a ring‐opening metathesis polymerization (ROMP) protocol to prepare functionalized polyacetylenes (fPAs) bearing: (1) electron‐deficient boryl (‐BR2) and phosphoryl (‐P(O)R2) side chains; (2) electron‐donating amino (‐NR2) groups, and (3) ring‐fused 1,2,3‐triazolium units via strain‐promoted Click chemistry. These functional groups render most of the fPAs soluble and can lead to intense light absorption across the visible to near‐IR region. Also, the presence of redox‐active boryl and amino groups leads to opposing near‐IR optical responses upon (electro)chemical reduction or oxidation. Some of the resulting fPAs show greatly enhanced air stability when compared to known polyacetylenes. Lastly, these fPAs can be cross‐linked to yield network materials with the full retention of optical properties.