New Publication

Akriti, Enzheng, and Stephen’s paper on Layer-by-Layer Anionic Diffusion in Two-Dimensional Halide Perovskite Vertical Heterostructures has been published in Nature Nanotechnology. Big congratulations!

Anionic diffusion in a soft crystal lattice of hybrid halide perovskites affects their stability, optoelectronic properties and the resulting device performance. The use of two-dimensional (2D) halide perovskites improves the chemical stability of perovskites and suppresses the intrinsic anionic diffusion in solid-state devices. However, a fundamental understanding of the role of organic cations in inhibiting anionic diffusion across the perovskite–ligand interface is missing. Here we demonstrate the first quantitative investigation of the anionic interdiffusion across atomically flat 2D vertical heterojunctions. A ‘quantized’ layer-by-layer diffusion model is proposed to describe the behaviour of the anionic migration in 2D halide perovskites. Our results provide important insights into the mechanism of anionic diffusion in 2D perovskites and provide a new materials platform with an enhanced stability for heterostructure integration.

This is is highlighted in Purdue Chemical Engineering newsroom, and many media.

New Graduate Students

The group welcomes two new graduate students: Qixuan Hu and Xi Wang. Qixuan got his BS in Chemical Engineering from University of Maryland in 2020, he will work on polymers and materials chemistry; Xi got his BS in Materials Science and Engineering from Beijing Institute of Technology in 2020, he will work on perovskite materials and devices. Welcome to the group!

Review paper

Enzheng’s review paper on halide perovskite heterostructures have been published in Accounts of Materials Research. This work is highlighted as an inside cover. Congratulations! This is a summary of our recent work in the past three years. Credits go to all my group members and collaborators. And a big thank you to Prof. Jiaxing Huang for the invitation!

A. Varma Fellowship

Akriti is selected to receive the Arvind Varma Fellowship in recognition of her great contribution in fundamental study of anion interdiffusion in perovskite heterostructures and her leadership in teaching and mentoring. Only 1 recipient each year from the school, in memorial of Prof. Arvind Varma, a giant in chemical engineering. Congratulations!

Visiting student from IIT

Ajeet Singh from IIT Delhi Department of Chemistry (with Prof. Sameer Sapra) is selected for the India’s Science and Engineering Research Board (SERB) Overseas Visiting Doctoral Fellowship (OVDF) and will stay with us from May 2021 to May 2022. Congratulations and look forward to working together!