Nuclear Techniques ›› 2016, Vol. 39 ›› Issue (12): 120101-120101.doi: 10.11889/j.0253-3219.2016.hjs.39.120101

• SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS •     Next Articles

Influences of precursor ratio on microstructure of perovskite CH3NH3PbI3 film and photoelectric conversion properties of perovskite solar cell

JI Gengwu1,2, ZHANG Xiaonan1,2, YANG Yingguo1,3, ZHAO Bin1,3, WEN Wen1,3, GAO Xingyu1,3   

  1. 1 Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jiading Campus, Shanghai 201800, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
  • Received:2016-09-18 Revised:2016-11-03 Online:2016-12-10 Published:2016-12-10
  • Supported by:

    Supported by National Natural Science Foundation of China (No.11175239, No.11605278, No.11675252)

Abstract:

Background: Organometal perovskite solar cells (PSCs) have attracted widespread consideration due to their conversion efficiency exceeding 20%. Because their outstanding photoelectric properties and their preparation process are often simple, among which one-step process has been most widely used. Purpose: This study aims to determine whether the mixing ratio of the precursor CH3NH3I and PbI2 is particularly critical for the preparation of CH3NH3PbI3 film, and thus influences the performance of PSCs. Methods: Synchrotron-based grazing incidence X-ray diffraction (GIXRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were employed to study the microstructure, surface morphology, chemical compositions of CH3NH3PbI3 film prepared using one-step process with different precursor (CH3NH3I and PbI2) ratios. Results: Results of GIXRD showed that the increase of CH3NH3I portion would reduce the degree of perovskite crystallinity with CH3NH3I and few PbI2 residue but enhance their preferential orientation along the out-of-plane direction, especially that of the perovskite (110) plane. In addition, a higher proportion of precursor CH3NH3I improved the surface morphology of the perovskite film with a better coverage as revealed by SEM. On the other hand, XPS results demonstrated that the increasing CH3NH3I portion caused Pb and I to enrich on the surface. Conclusion: The present study explored the influence of the mixing ratios of the precursors on the microstructure, surface morphology of perovskite films, as well as the device performance, which would provide experimental basis and guidance for preparing perovskite films for high performance perovskite solar cells with improved stability.

Key words: Perovskite film, Precursor ratio, GIXRD

CLC Number: 

  • TL99