High‐Quality Mixed‐Organic‐Cation Perovskites from a Phase‐Pure Non‐stoichiometric Intermediate (FAI)_1−x‐PbI₂ for Solar Cells

Abstract

A high-quality mixed-organic-cation perovskite (MA)x (FA)1- x PbI3 is prepared from a phase-pure non-stoichiometric intermediate complex (FAI)1- x -PbI2 . The phase-pure (FAI)1- x -PbI2 probably facilitates homogenous nucleation and modulates the growth kinetics during the crystallization of (MA)x (FA)1- x PbI3 . This strategy can be expected to pave the way for the development of mixed-organic-cation perovskite solar cells.

Improving the efficiency of inverted mixed-organic-cation perovskite absorber based photovoltaics by tailing the surface roughness of PEDOT: PSS thin film

“…There is an increase in the position of the diffraction peak at (1 1 0) gradually from 14.01°to 14.20°with an increase in the addition of MAI, which is due to the smaller size of the MA cations as compared with that of the FA cations. For the FAPbI 3 based photovoltaics, the existences of d-FAPbI 3 and PbI 2 lead to a degradation of the PCE (Pellet et al, 2014;Liu et al, 2015). The addition of MAI can eliminate the formations of d-FAPbI 3 and PbI 2 in the FA x MA 1Àx PbI 3 thin films as shown in Fig.…”

“…MAI and FAI were synthesized by the same methods as published in the references Liu et al (2015) and Etgar et al (2012). The FA x MA 1Àx PbI 3 precursor was spin-coated on top of the PEDOT:PSS/ITO/glass using an in-situ non-polar solvent washing treatment.…”

“…Mixed-organiccation perovskite absorbers (MOC-PAs) composed of MAPbI 3 and FAPbI 3 , which can be fabricated by two-step solution processes http://dx.doi.org/10.1016/j.solener.2016.05.032 0038-092X/Ó 2016 Elsevier Ltd. All rights reserved. (Pellet et al, 2014;Liu et al, 2015), which have a broad light absorption spectrum while keeping the phase stable in an ambient humid atmosphere. In a regular structure, the averaged PCE of the MOC-PA based photovoltaics fabricated by the sequential deposition processes is 13.4% (Pellet et al, 2014) because of the low short-circuit current density (J SC ).…”

“…The low J SC is possible due to the formation of PbI 2 which limits the light harvesting and the carrier extraction. In an inverted structure fabricated under the low temperatures (<120°C), the averaged PCE of the phase-pure MOC-PA based photovoltaics fabricated by the two-step spincoating process will be 11.5% (Liu et al, 2015) with a low J SC and a moderate open-circuit voltage (V OC ).…”

The Emergence of the Mixed Perovskites and Their Applications as Solar Cells

“…The pure-phase mixed MA x FA 1−x PbI 3 crystals with relatively long fluorescence lifetimes possess less defects and more regular grain morphologies, which suppress charge recombination and facilitate charge transport, resulting in higher V oc , short-circuit current (J sc ) and PCE compared to that of MAPbI 3 . In addition, Huang et al [66] [65] Copyright 2015, Wiley-VCH. c) and d) show the successive changes of absorption and normalized XRD spectra of MAPbI 3 −FAPbI 3 thin films during the conversion from MAPbI 3 to MAPbI 3 −FAPbI 3 enabled by cation exchange, respectively.…”