Unveiling Structurally Engineered Carrier Dynamics in Hybrid Quasi-Two-Dimensional Perovskite Thin Films toward Controllable Emission

Qiuyu Shang; Yunuan Wang; Yangguang Zhong; Yang Mi; Liang Qin; Yuefeng Zhao; Xiaohui Qiu; Xinfeng Liu; Qing Zhang

doi:10.1021/acs.jpclett.7b01857

Unveiling Structurally Engineered Carrier Dynamics in Hybrid Quasi-Two-Dimensional Perovskite Thin Films toward Controllable Emission

J Phys Chem Lett. 2017 Sep 21;8(18):4431-4438. doi: 10.1021/acs.jpclett.7b01857. Epub 2017 Sep 5.

Authors

Qiuyu Shang¹, Yunuan Wang^{1

2}, Yangguang Zhong^{1

3}, Yang Mi³, Liang Qin³, Yuefeng Zhao², Xiaohui Qiu³, Xinfeng Liu³, Qing Zhang^{1

4}

Affiliations

¹ Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, China.
² School of Physics and Electronics, Shandong Normal University , Jinan 250014, China.
³ CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology , Beijing 100190, China.
⁴ Research Center for Wide Gap Semiconductor, Peking University , Beijing 100871, China.

PMID: 28845670
DOI: 10.1021/acs.jpclett.7b01857

Abstract

Quasi-two-dimensional Ruddlesden-Popper perovskites driving carrier self-separation have rapidly advanced the development of high-performance optoelectronic devices. However, insightful understanding of carrier dynamics in the perovskites is still inadequate. The distribution of multiple perovskite phases, crucial for carrier separation, is controversial. Here we report a systematic study on carrier dynamics of spin-coated (C₆H₅CH₂CH₂NH₃)₂(CH₃NH₃)_n-1Pb_nI_3n+1 (n = 3 and 5) perovskite thin films. Efficient electrons transfer from small-n to large-n perovskite phases, and holes transfer reversely with time scales from ∼0.3 to 30.0 ps. The multiple perovskite phases are arranged perpendicularly to substrate from small to large n and also coexist randomly in the same horizontal planes. Further, the carrier separation dynamics is tailored by engineering the crystalline structure of the perovskite film, which leads to controllable emission properties. These results have important significance for the design of optoelectronic devices from solar cells, light-emitting diodes, lasers, and so forth.