New publication

Zitang (Tim)’s work entitled “Side-Chain Control of Topochemical Polymer Single Crystals with Tunable Elastic Modulus” has been published in Angew. Chem. Int. Ed. Congratulations!

In this work, we report a systematic study on the side chain functionalization of the bis(indandione) derivative system that can be polymerized under visible light. Precisely engineered side chains help organize the monomer crystals in a one-dimensional fashion to facilitate polymerization and improve mechanical properties. Read the story here.

Visiting Scholar

We welcome Dr. Sung-Doo Baek, a research professor from Department of Materials Science and Engineering of Yonsei University, visiting us for 6 months. Dr. Baek is an expert on perovskite LEDs. Welcome to the group and look forward to working together!

New Publication

Xuyi, Zitang, and Bumjoon’s work on recyclable polymers featuring topochemically elongated and weakened carbon–carbon bonds has been published in JACS! Big congratulations!

We demonstrate a topochemical approach for creating elongated C–C bonds with a bond length of 1.57∼1.63 Å between repeating units with decreased bond dissociation energies. These materials exhibit rapid depolymerization via breakage of the elongated bond within a desirable temperature range (140∼260 °C) while otherwise remaining remarkably stable under harsh conditions. The topochemically prepared polymers are processable and 3D-printable while maintaining a high depolymerization yield and tunable mechanical properties. These results suggest that the crystalline polymers synthesized from simple photochemistry and without expensive catalysts are promising for practical applications with complete materials’ circularity. Read the paper here. Read a Blog on Medium here.

New Publication

Aidan’s paper entitled “Controlling Crystallization of Quasi-2D Perovskite Solar Cells: Incorporating Bulky Conjugated Ligands” has been published in Advanced Energy Materials. Congratulations!

A bulky bi-thiophene 2T ligand is used to create vertically-aligned quasi-2D perovskite films. By starting with a poorly coordinating solvent (GBL) and adding a small amount of DMSO and methanol, it is found that vertical orientation and z-uniformity is greatly improved. These are examined using grazing-incidence wide-angle X-ray scattering and advanced optical characterizations. Solar cells with an max efficiency of 13.3% are demonstrated. The quasi-2D absorbing layers show excellent stability in moisture, remaining unchanged after hundreds of hours. Read the story here.

Visiting UG

Undergrad visiting students Xinan Wu and Peiran Niu, both from Peking University Physics Department, joined the group. Xinan will work on OSiP LEDs and Peiran will work on large area solar cells. Welcome to the group and look forward to working together!