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  • 2D Homologous Perovskites as Light-Absorbing Materials for Solar Cell Applications.

2D Homologous Perovskites as Light-Absorbing Materials for Solar Cell Applications.

Journal of the American Chemical Society (2015-05-29)
Duyen H Cao, Constantinos C Stoumpos, Omar K Farha, Joseph T Hupp, Mercouri G Kanatzidis
ABSTRACT

We report on the fabrication and properties of the semiconducting 2D (CH3(CH2)3NH3)2(CH3NH3)(n-1)Pb(n)I(3n+1) (n = 1, 2, 3, and 4) perovskite thin films. The band gaps of the series decrease with increasing n values, from 2.24 eV (CH3(CH2)3NH3)2PbI4 (n = 1) to 1.52 eV CH3NH3PbI3 (n = ∞). The compounds exhibit strong light absorption in the visible region, accompanied by strong photoluminescence at room temperature, rendering them promising light absorbers for photovoltaic applications. Moreover, we find that thin films of the semi-2D perovskites display an ultrahigh surface coverage as a result of the unusual film self-assembly that orients the [Pb(n)I(3n+1)](-) layers perpendicular to the substrates. We have successfully implemented this 2D perovskite family in solid-state solar cells, and obtained an initial power conversion efficiency of 4.02%, featuring an open-circuit voltage (V(oc)) of 929 mV and a short-circuit current density (J(sc)) of 9.42 mA/cm(2) from the n = 3 compound. This result is even more encouraging considering that the device retains its performance after long exposure to a high-humidity environment. Overall, the homologous 2D halide perovskites define a promising class of stable and efficient light-absorbing materials for solid-state photovoltaics and other applications.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
di-n-butylammonium dimethylammonium lead(II) decaiodide, n = 3
Sigma-Aldrich
di-n-butylammonium lead(II) tetraiodide, n = 1