High‐Performance Perovskite Solar Cells with Large Grain‐Size obtained by using the Lewis Acid‐Base Adduct of Thiourea

Abstract

Recently, perovskite solar cells (PSCs) have been rapidly developed, counting as the most promising alternative to the Si solar cells. The fabrication of perovskite films with controlled crystallinity and grain size is critical for highly efficient and stable solar cells. In this work, thiourea (TU) serving as a Lewis acid‐base adduct is introduced into the CH3NH3PbI3 precursor. A smooth and large grained perovskite crystal is obtained without the intermediate phase PbI2 · SC(NH2)2 using the ideal thiourea amount. Thiourea, through forming MAI · PbI2 · DMSO · thiourea in perovskite precursor solution, significantly impacts the perovskite crystallinity and morphology, as proved using X‐ray diffraction patterns and infrared spectroscopy. Light harvesting, suppressed defect state, and enhanced charge separation and transport of the perovskite absorber layer are improved. The optimum performance of perovskite solar cells with TU demonstrated a power conversion efficiency (PCE) of 19.80%, an average steady‐state PCE of 18.60% and potent stability under ambient air.

Toward Efficient and Stable Perovskite Solar Cells: Choosing Appropriate Passivator to Specific Defects

“…[ 132 ] Common S donor Lewis bases mainly include thiophene, thiourea, and their derivatives. [ 86–88,133,134 ] Yang et al introduced derivatives of thiophene IT‐M molecules as Lewis base to successfully passivate the surface defects (the uncoordinated Pb 2+ ) by donating electrons, enhancing the photoluminescence (PL) lifetime to 2.2 μs and further raising the PCE up to 20.5% with a FF as high as 0.81. [ 88 ] Ko et al introduced thiourea as an additive in the MAPbI x Cl 3– x precursor solution to boost the performances and stabilities of fully printable PSCs.…”

Effect of Cu2O Content in Electrodeposited CuOx Film on Perovskite Solar Cells

“…In recent years, due to the energy crisis and the environmental damage caused by the burning of fossil energy, renewable energy has received more and more attention. [1][2][3][4][5] Due to the power conversion e±ciency (PCE), low preparation cost and high light absorption of hybrid perovskite solar cells (PSCs), it becomes the most promising photovoltaic cells. [6][7][8][9][10][11] The PCE of the PSCs has increased from 3.8% by Miyasaka et al 12 to 23.2% by Jeon et al 13 in just 10 years.…”

Interface Engineering in n‐i‐p Metal Halide Perovskite Solar Cells

“…Trioctylphosphine oxide (TOPO) and triphenylphosphine oxide (TPPO) were also reported as O‐donor Lewis bases to passivate MHP films effectively, resulting in an extended carrier lifetime of 8 µs and improved PCE (Figure c) . Other Lewis bases such as fullerene, π‐conjugated IDIC and PBDB‐T, non‐fullerene acceptor IT‐M, 2,6‐dimethoxypyridine, caprolactam, thiourea, and fluorine‐containing hydrophobic Lewis acid have also demonstrated success. Recently, Gao et al reported an unencapsulated devices with an active area of 1.0 cm 2 retaining 93% of the original PCE of 17.67% after 2 months under air conditions.…”