Crystallization and Orientation Modulation Enable Highly Efficient Doctor-Bladed Perovskite Solar Cells

Abstract

With the rapid rise in perovskite solar cells (PSCs) performance, it is imperative to develop scalable fabrication techniques to accelerate potential commercialization. However, the power conversion efficiencies (PCEs) of PSCs fabricated via scalable two-step sequential deposition lag far behind the state-of-the-art spin-coated ones. Herein, the additive methylammonium chloride (MACl) is introduced to modulate the crystallization and orientation of a two-step sequential doctor-bladed perovskite film in ambient conditions. MACl can significantly improve perovskite film quality and increase grain size and crystallinity, thus decreasing trap density and suppressing nonradiative recombination. Meanwhile, MACl also promotes the preferred face-up orientation of the (100) plane of perovskite film, which is more conducive to the transport and collection of carriers, thereby significantly improving the fill factor. As a result, a champion PCE of 23.14% and excellent long-term stability are achieved for PSCs based on the structure of ITO/SnO2/FA1-xMAxPb(I1-yBry)3/Spiro-OMeTAD/Ag. The superior PCEs of 21.20% and 17.54% are achieved for 1.03 cm2 PSC and 10.93 cm2 mini-module, respectively. These results represent substantial progress in large-scale two-step sequential deposition of high-performance PSCs for practical applications.

Healing the Buried Interface by a Plant-Derived Green Passivator for Carbon-Based CsPbIBr2 Perovskite Solar Cells

“…The trap-filled limit voltage ( V TFL ) is smaller (Figure g), indicating the decreased defect density ( N t ) from 1.34 × 10 16 cm –3 for the pristine film to 1.28 × 10 16 cm –3 for the ET-modified film according to the following equation: N t = 2εε 0 V TFL / qL 2 , where q is the elementary charge, ε 0 represents the vacuum permittivity, and L and ε are the thickness and relative dielectric constant of the perovskite film. In this fashion, upon the light irradiation, the photogenerated carriers can exist longer before being capped by defects, simultaneously leading to the preferred irradiative recombination, namely, increased photoluminescence (PL) intensity. , As expected, the PL intensity of the ET-tailored perovskite film is significantly enhanced (Figure h), evidently indicating the less trap-state density and suppressed nonradiative recombination loss. , Time-resolved PL (TRPL) decay curves were recorded and the plots were fitted by a biexponential decay function to evaluate the carrier lifetime as follows: I = γ 0 + A 1 exp­(− t /τ 1 ) + A 2 exp­(− t /τ 2 ), where γ 0 is the decay constant, A 1 and A 2 are amplitudes, τ 1 is bimolecular recombination of photogenerated carriers, and τ 2 is trap-assisted recombination. , The detailed fitted results are given in Table S1. After calculation, the average lifetime (τ ave ) is prolonged from 2.41 to 3.50 ns after modification by ET (Figure i).…”

“…46,47 As expected, the PL intensity of the ET-tailored perovskite film is significantly enhanced (Figure 2h), evidently indicating the less trap-state density and suppressed nonradiative recombination loss. 48,49 Time-resolved PL (TRPL) decay curves were recorded and the plots were fitted by a biexponential decay function to evaluate the carrier lifetime as follows:…”

Room-Temperature Processed Annealing-Free Printable Carbon-Based Mesoscopic Perovskite Solar Cells with 17.34% Efficiency

“…As illustrated in Figure 4b,c, the bright diffraction ring at scattering vector q ≈ 1.0 Å −1 is attributed to the (110) crystal plane of perovskite, while q ≈ 0.9 Å −1 corresponds to the (001) crystal plane of PbI 2 . 34,35 The control sample exhibits weaker diffraction rings and a relatively uniform azimuthal intensity distribution, indicating irregular crystal orientation and weak crystallinity, consistent with the results discussed in the XRD above. In contrast, the perovskite treated with 5 mol % NH 4 Cl shows brighter and stronger diffraction spots, suggesting preferred crystal orientation growth, which is beneficial for preparing perovskite with excellent crystallization performance in mesopores.…”

Enhancing Efficiency of Large-Area Wide-Bandgap Perovskite Solar Modules with Spontaneously Formed Self-Assembled Monolayer Interfaces

“…Noteworthily, the target film exhibits a longer average carrier lifetime (141.58 ns), almost twice as long as the control film (74.24 ns), which indicates that defect-assisted nonradiative recombination in the target film is effectively suppressed due to increased grain size, enhanced crystallinity, and diminished defect density. Defects within perovskite films commonly serve as nonradiative recombination centers for charge carriers . To further quantitatively assess the trap-state density of the devices, hole-only devices with the structure of glass/ITO/SAMs/perovskite/MoO 3 /Ag were constructed for space-charge-limited-current (SCLC) measurements, as shown in Figure i.…”