Letian Dou Group

Qixuan Hu passes his qualifier exam and now become a PhD candidate. Big congratulations! Many new exciting projects are ahead. Good luck!

Our senior postdoc fellow Dr. Yao Gao, who jointed the group in Oct 2017 and carried out amazing foundational work for the group, has decided to join Huazhong University of Science and Technology as a professor of materials science and engineering. He will be leaving the group this month. Big congratulations! Good luck with your future endeavors!

Akriti, Shuchen, and Zih-Yu’s work regarding anion diffusion in two-dimensional halide perovskite lateral heterostructures in Adv. Mater. — where Dr. Dou is featured in the “Rising Stars” inaugural issue. Another great collaboration with Savoie group. Read the story here.

Zitang (Tim)’s work on selenophene containing conjugated ligands for OSiPs in Chem. Comm. — where Dr. Dou is featured as “Emerging Investigator” special issue. Read the story here.

Aihui and Yao’s work entitled “Ligand-Driven Grain Engineering of High Mobility Two-Dimensional Perovskite Thin-Film Transistors” has been published in JACS. We demonstrate field-effect transistors of a novel 2D OSiP with hole mobility approaching 10 cm² V^–1 s^–1 with ON/OFF current ratios of ∼10⁶ and excellent stability and reproducibility. Great collaboration with Prof. M. Ashraf Alam group and many others. Congratulations! Read the story here.

The group warmly welcomes two new postdoc fellows Dr. Yoon Ho Lee and Dr. Jiaonan Sun joining us. Dr. Lee received his PhD in Chemical Engineering from POSTECH with Prof. Joon Hak Oh. He will be co-advised by Prof. Dou and Prof. Mei on perovskite solar cells. Dr. Jiaonan Sun received her PhD in Chemistry from Ohio State University with Prof. Yiying Wu. She will work on developing novel and stable OSiPs for solar cells and LEDs. Welcome to the group. Look forward to working together!

Sheng-Ning and Wenchao’s paper about understanding thermoelectric properties of lead-free 2D OSiPs [Organic Semiconductor-incorporated Perovskites] have been published in Nano Letters. Both of them are co-advised with Prof. Boudouris. Wonderful collaborations. Big congratulations!! Read the story here.

The group receives new funding supports from Department of Energy Office of Basic Energy Sciences (with Prof. Libai Huang group) working on exciton and spin transports in 2D perovskites and National Science Foundation Division of Electrical, Communications and Cyber Systems (with Prof. Hanwei Gao at Florida State Univ.) working on perovskite LEDs. Thanks DOE and NSF for the supports!

Ke’s paper entitled “Multifunctional Conjugated Ligand Engineering for Stable and Efficient Perovskite Solar Cells” has been published in Advanced Materials. Read the story here.

We report a novel multifunctional semiconducting organic ammonium cationic interface modifier inserted between the light-harvesting perovskite film and the hole-transporting layer. It is shown that the conjugated cations can directly extract holes from perovskite efficiently, and simultaneously reduce interface non-radiative recombination. Together with improved energy level alignment and the stabilized interface in the device, a triple-cation mixed-halide medium-bandgap solar cell with an excellent power conversion efficiency of 22.06% (improved from 19.94%) and suppressed ion migration and halide phase segregation, which lead to a long-term operational stability, is demonstrated.

Yao’s perspective entitled “Organic semiconductor-incorporated two-dimensional halide perovskites” has been published in National Science Review. Read the story here.

In this perspective article, we defined OSiP: Organic Semiconductor-incorporated Halide Perovskites; and discussed recent progress toward this exciting new direction concisely.

The group welcomes a visiting undergraduate student, Martin Gomez Dominguez, from Universidad de los Andes of Colombia. Martin will stay for the summer and work on halide perovskite solar cells. Welcome to Purdue!