Abstract
Incorporating additives into organic halide perovskite solar cells is the typical approach to improve power conversion efficiency. In this paper, a methyl-ammonium lead iodide (CH3NH3PbI3, MAPbI3) organic perovskite film was fabricated using a two-step sequential process on top of the poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) hole-transporting layer. Experimentally, water and potassium halides (KCl, KBr, and KI) were incorporated into the PbI2 precursor solution. With only 2 vol% water, the cell efficiency was effectively improved. Without water, the addition of all of the three potassium halides unanimously degraded the performance of the solar cells, although the crystallinity was improved. Co-doping with KI and water showed a pronounced improvement in crystallinity and the elimination of carrier traps, yielding a power conversion efficiency (PCE) of 13.9%, which was approximately 60% higher than the pristine reference cell. The effect of metal halide and water co-doping in the PbI2 layer on the performance of organic perovskite solar cells was studied. Raman and Fourier transform infrared spectroscopies indicated that a PbI2-dimethylformamide-water related adduct was formed upon co-doping. Photoluminescence enhancement was observed due to the co-doping of KI and water, indicating the defect density was reduced. Finally, the co-doping process was recommended for developing high-performance organic halide perovskite solar cells.
Highlights
The first report on lead halide organic perovskites for photovoltaic applications was published in 2009 [1]
We proposed an effective way to enhance the efficiency of the MAPbI3-based perovskite device through the co-doping of water and potassium halides (KI, KBr, and KCl) during the PbI2 deposition process
A way to improve the perovskite solar cells was proposed by co-doping water and potassium halides in the PbI2 layer, which was coated on the PEDOT:PSS layer based in a two-step sequential process
Summary
The first report on lead halide organic perovskites for photovoltaic applications was published in 2009 [1]. Kojima et al used methylammonium lead iodide (CH3NH3PbI3, MAPbI3) to replace organic dyes in dye-sensitized solar cells (DSSCs), where mesoporous titanium oxide (TiO2) and a liquid electrolyte were used, achieving a power conversion efficiency (PCE) of 3.8%. PCE of the MAPbI3-based solar cell has been close to 20% in both mesoporous structure devices [3] as well as in planar heterojunction architectures [4]. High temperature annealing (>400 ◦C) is required to crystallize the TiO2 layers used in mesoporous-type solar cells. Compared to the high-temperature processing of mesoporous solar cells, the planar heterojunction perovskite photovoltaics has the advantage of a low-temperature (100 ◦C) solution process, and, can be adopted in the roll-to-roll production of flexible devices [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
