Compact layer free perovskite solar cells with 13.5% efficiency

J Am Chem Soc. 2014 Dec 10;136(49):17116-22. doi: 10.1021/ja508758k. Epub 2014 Nov 26.

Abstract

The recent breakthrough of organometal halide perovskites as the light harvesting layer in photovoltaic devices has led to power conversion efficiencies of over 16%. To date, most perovskite solar cells have adopted a structure in which the perovskite light absorber is placed between carrier-selective electron- and hole-transport layers (ETLs and HTLs). Here we report a new type of compact layer free bilayer perovskite solar cell and conclusively demonstrate that the ETL is not a prerequisite for obtaining excellent device efficiencies. We obtained power conversion efficiencies of up to 11.6% and 13.5% when using poly(3-hexylthiophene) and 2,2',7,7'-tetrakis(N,N-di(4-methoxyphenyl)amino)-9,9'-spirobifluorene, respectively, as the hole-transport material. This performance is very comparable to that obtained with the use of a ZnO ETL. Impedance spectroscopy suggests that while eliminating the ZnO leads to an increase in contact resistance, this is offset by a substantial decrease in surface recombination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electric Power Supplies*
  • Electrons
  • Solar Energy*
  • Surface Properties