Low‐Pressure Vapor‐Assisted Solution Process for Thiocyanate‐Based Pseudohalide Perovskite Solar Cells

Abstract

In this report, we fabricated thiocyanate-based perovskite solar cells with low-pressure vapor-assisted solution process (LP-VASP) method. Photovoltaic performances are evaluated with detailed materials characterizations. Scanning electron microscopy images show that SCN-based perovskite films fabricated using LP-VASP have long-range uniform morphology and large grain sizes up to 1 μm. The XRD and Raman spectra were employed to observe the characteristic peaks for both SCN-based and pure CH NH PbI perovskite. We observed that the Pb(SCN) film transformed to PbI before the formation of perovskite film. X-ray photoemission spectra (XPS) show that only a small amount of S remained in the film. Using LP-VASP method, we fabricated SCN-based perovskite solar cells and achieved a power conversion efficiency of 12.72 %. It is worth noting that the price of Pb(SCN) is only 4 % of PbI . These results demonstrate that pseudo-halide perovskites are promising materials for fabricating low-cost perovskite solar cells.

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

“…The replacement of two iodides by SCN − significantly boosted the moisture tolerance ( Figure 16 ). Moreover, Pb(SCN) 2 is much cheaper than PbI 2 . They suggested that the lone pair electrons of the linear shaped SCN − interact more strongly with the Pb ion than that of the spherical I − , which is beneficial for stabilizing the PVSK structure.…”

Highly Reproducible Large‐Area Perovskite Solar Cell Fabrication via Continuous Megasonic Spray Coating of CH3NH3PbI3

“…As the perovskite film thickness increases, the short circuit current density ( J SC ) is enhanced due to augmented photonic absorption ( Figure and Figure S2b, Supporting Information). A small change in J SC is due to the J SC having already reached almost maximum photocurrent density of MAPbI 3 based perovskite solar cell (≈22.61 mA cm −2 ) . Because the fabricated perovskite films have enough thickness (400–900 nm) to absorb incident light.…”

“…The inset in Figure a is the equivalent circuit employed to fit the spectra . In the equivalent circuit, a series resistance ( R s ) is used to model the interface resistance of the ITO substrate, and the interface of the selective contacts (SCs) with the perovskite layer are represented by the SC resistance ( R sc ) and SC capacitance ( C sc ) components . R rec and C ps are the recombination resistance and the perovskite layer capacitance, respectively .…”

Recent progress in stabilizing hybrid perovskites for solar cell applications

“…Robert L. Z. Hoye et al explored methylammonium bismuth iodide as a lead-free, stable hybrid organicinorganic solar absorber [318,319] . Replacing chemical reactive halide ions with more robust pseudohalogen polyanions appears to be a promising approach for enhancing the chemical stability of perovskites [320][321][322][323][324][325][326] . Tao Xu et al [322] replaced two iodides in CH 3 NH 3 PbI 3 by two pseudohalide thiocyanate ions (SCN -) to form CH 3 NH 3 Pb(SCN) 2 I.…”