Ultracompact, Well-Packed Perovskite Flat Crystals: Preparation and Application in Planar Solar Cells with High Efficiency and Humidity Tolerance

Abstract

Planar perovskite solar cells (PSCs) have exhibited a promising alternative for high efficiency recently because of a new record of certified power conversion efficiency (PCE) of 21.5%. At the present stage of PSCs, achieving further improvements for long-term stability and efficiency are the key issues. It is necessary to fabricate PSCs with good interface and film crystallinity. Here, planar PSCs are fabricated by a synergistic effect of dimethyl sulfoxide additive and a dropwise addition method in a two-step deposition method. Under the optimizing procedure, a large-grain perovskite film with well-packed flat crystals is induced with a largest grain size of about 5 μm, which reveals decreased defect states owing to reduced grain boundaries. Moreover, the film has a highly compact and flat surface, leading to high crystallinity, enhanced light absorption, and low carrier recombination rates. Corresponding PCE is significantly promoted to 20.63% from the original 16.02%. More importantly, the PSCs even without encapsulation exhibit excellent humidity stability, retaining 93% of its initial efficiency after 500 h in air with 40% humidity, whereas the pristine devices degrade by approximately 65% after only surviving for 256 h. Therefore, the result provides a promising route for preparation of large-grain perovskite films and high-performance and stable PSCs.

Architecturing Lattice-Matched Bismuthene–SnO2 Heterojunction for Effective Perovskite Solar Cells

“…Figure a–e shows samples A, B, C, D, and E in the top view, respectively, and the corresponding grain size distribution maps are accurately analyzed and shown in their insets. Generally, their surfaces are all blocklike and smooth, in accordance with the characteristics in the literature . It is clear that the size of the perovskite crystal obviously changes with different bismuthene contents, and the average grain sizes of samples A, B, C, D, and E are measured as 0.82, 0.94, 1.02, 0.97, and 0.96 μm, respectively.…”

“…These require complex technologies and an expensive processing environment. In addition, a PCE of 20.63% with only 0.03 hysteresis was also achieved with the SnO 2 ETL in our previous work . To achieve high PCE, a dropwise addition method is employed to subtly fabricate the perovskite layer for achieving larger grain sizes.…”

Efficient Two-Dimensional Perovskite Solar Cells Realized by Incorporation of Ti3C2Tx MXene as Nano-Dopants

“…5 b, with the equivalent circuit model displayed in the inset. Here, R s represents the series resistance, which primarily reflects the electrical contacts, wires, and sheet resistance of the electrodes [ 53 ]. The charge-transfer properties at the interface are reflected by the charge-transfer resistance ( R tr ), whereas R rec is related to the recombination of the carriers [ 54 ].…”

Low-Temperature Growing Anatase TiO2/SnO2 Multi-dimensional Heterojunctions at MXene Conductive Network for High-Efficient Perovskite Solar Cells

“…The series resistance (R s ) mainly reflects electrical contacts, wires, and sheet resistance of the electrodes [43,53]. The charge-transfer resistance (R tr ) means the charge-transfer property at the interface, and R rec means the recombination of carriers [43,54]. Fitted with ZView software, it can be observed that the R s values are similar for these samples.…”

“…The perovskite layer with (FAPbI 3 ) 0.97 (MAPbBr 3 ) 0.03 was fabricated on the ETL by a two-step deposition strategy as described in our previous work [ 21 , 43 ]. In belief, 1.3 M PbI 2 in the mixture solvent of DMF/DMSO (9.5:0.5, by volume) was spin-coated onto the ETL at 1500 rpm for 30 s and then annealed at 70 °C for 1 min in N 2 atmosphere in a glove box.…”