Publication

Pure crystal orientation and anisotropic charge transport in large-area hybrid perovskite films

​Pure crystal orientation and anisotropic charge transport in large-area hybrid perovskite films
Namchul Cho, Feng Li, Bekir Turedi, Lutfan Sinatra, Smritakshi P. Sarmah, Manas R. Parida, Makhsud I. Saidaminov, Banavoth Murali, Victor M. Burlakov, Alain Goriely, Omar F. Mohammed, Tom Wu & Osman M. Bakr
Nature Communications 7, Article number: 13407 (2016)
Namchul Cho, Feng Li, Bekir Turedi, Lutfan Sinatra, Smritakshi P. Sarmah, Manas R. Parida, Makhsud I. Saidaminov, Banavoth Murali, Victor M. Burlakov, Alain Goriely, Omar F. Mohammed, Tom Wu, Osman M. Bakr
crystal, hybrid perovskite film
2016

Controlling crystal orientations and macroscopic morphology is vital to develop the electronic properties of hybrid perovskites. Here we show that a large-area, orientationally pure crystalline (OPC) methylammonium lead iodide (MAPbI3) hybrid perovskite film can be fabricated using a thermal-gradient-assisted directional crystallization method that relies on the sharp liquid-to-solid transition of MAPbI3 from ionic liquid solution. We find that the OPC films spontaneously form periodic microarrays that are distinguishable from general polycrystalline perovskite materials in terms of their crystal orientation, film morphology and electronic properties. X-ray diffraction patterns reveal that the film is strongly oriented in the (112) and (200) planes parallel to the substrate. This film is structurally confined by directional crystal growth, inducing intense anisotropy in charge transport. In addition, the low trap-state density (7.9 × 1013 cm−3) leads to strong amplified stimulated emission. This ability to control crystal orientation and morphology could be widely adopted in optoelectronic devices.

 

doi:10.1038/ncomms13407