Fabrication and Characterization of CH₃NH₃PbI₃ Perovskite Solar Cells Added with Polysilanes

Abstract

Effects of polysilane additions on CH3NH3PbI3 perovskite solar cells were investigated. Photovoltaic cells were fabricated by a spin-coating method using perovskite precursor solutions with polymethyl phenylsilane, polyphenylsilane, or decaphenyl cyclopentasilane (DPPS), and the microstructures were examined by X-ray diffraction and optical microscopy. Open-circuit voltages were increased by introducing these polysilanes, and short-circuit current density was increased by the DPPS addition, which resulted in the improvement of the photoconversion efficiencies to 10.46%. The incident photon-to-current conversion efficiencies were also increased in the range of 400~750 nm. Microstructure analysis indicated the formation of a dense interfacial structure by grain growth and increase of surface coverage of the perovskite layer with DPPS, and the formation of PbI2 was suppressed, leading to the improvement of photovoltaic properties.

Development of Polysilane-Inserted Perovskite Solar Cells

“…By incorporating DPPS between the perovskite and HTL, effective hole transport from the valence band of the perovskite to the Au electrode was induced. This smooth transport was also due to the molecular structure of DPPS [13,16,38].…”

“…The second derives from polysilanes having high stabilities at elevated temperatures up to ~300 °C and therefore expected to act as a protective layer across the perovskite surface. In addition, polysilanes have been applied to perovskite solar cells [14], and the photovoltaic properties were improved, especially by adding decaphenylcyclopentasilane (DPPS) [15,16]. The previously reported perovskite layers were a standard MAPbI3 compound, so further studies focusing on doped MAPbI3 compounds [17][18][19] are required to further elucidate the applicability of DPPS for perovskite solar cells.…”

Crystal structures of perovskite halide compounds used for solar cells

“…Device performances are also dependent on the microstructures of thin film configurations, and the morphology can be controlled by additives such as poly(methyl methacrylate) [88][89][90], phthalocyanines [91][92][93][94], or polysilanes [95][96][97]. A large contact area at the TiO 2 /perovskite interface can enhance the probability of carrier separation, which improves the short circuit current density.…”

Photovoltaic Characteristics of CH3NH3PbI3 Perovskite Solar Cells Added with Ethylammonium Bromide and Formamidinium Iodide

“…The 0.15 and 0.30 M precursor solutions of TiO 2 were prepared from 0.055 and 0.11 mL titanium disopropoxide bis (acetyl acetonate) (Sigma Aldrich, Tokyo, Japan) and 1-btanol (1.0 mL, Nacalai Tesque, Kyoto, Japan). The solutions were cast on the transparent FTO, and spin-coated at 3000 rpm for 30 s and heat-treated at 125 • C for 5 min [37][38][39]. The processes with 0.30 M precursor solutions were repeated twice.…”