Perovskitoid‐Templated Formation of a 1D@3D Perovskite Structure toward Highly Efficient and Stable Perovskite Solar Cells

Abstract

Longevity is a long‐standing concern for organic–inorganic hybrid perovskite solar cells (PSCs). Recently, the use of low dimensional perovskite has been proven to be a promising strategy to improve the stability of PSCs. Herein, it is demonstrated that 1D perovskitoid based on 2‐diethylaminoethylchloride cations can act as a template to induce 1D@3D perovskite structure, leading to smoother surface texture, longer charge‐carrier lifetime, smaller residual tensile strain, and reduced surface‐defect density in the perovskite film. With this strategy, highly efficient and stable 1D@3D PSC with excellent reproducibility, showing a champion power conversion efficiency (PCE) of 22.9% under standard AM 1.5 G one sun illumination is realized. The unencapsulated optimized devices can retain 94.7%, 92.4%, and 90.0% of their initial PCEs for 2100, 2200, and 2200 h under ambient air, 85 °C and illumination conditions, respectively.

Temperature‐Reliable Low‐Dimensional Perovskites Passivated Black‐Phase CsPbI3 toward Stable and Efficient Photovoltaics

“…After heating at 190 °C for 10 min, however, the PEA 2 PbI 4 decomposed into PbI 2 (Figure S10 and S11), indicating that the 2D PEA 2 PbI 4 is thermally unstable at relatively high temperature; [19] therefore, it cannot exist in the final CsPbI 3 films. Conversely, 2D PTA 2 PbI 4 basically can bear an annealing treatment at 190 °C, and a new diffraction peak at 8.42° appears with a new absorption peak at 372 nm (Figure S12 and S13), which might be a typical 1D PTAPbI 3 perovskite based on previous studies, [9, 16e–g, 20] and also in good accordance with the simulated XRD result (Figure S14). Therefore, among the three OAI salts, only PTAI can give thermally stable LD perovskites at 190 °C or even higher temperature (Figure S15).…”

Mixed Dimensional Perovskites Heterostructure for Highly Efficient and Stable Perovskite Solar Cells

“…However, for 1D/3D perovskite films, they are shifted to 138.6 and 143.4 eV, respectively, could be ascribed to the strong electronic interactions between Me 3 SI and Pb 2+ due to the formation of Pb—S bond. [ 51,52 ] In addition, two small peaks are also observed at 136.6 and 141.5 eV assigned to the Pb 0 4f 7/2 and Pb 0 4f 5/2 for 3D perovskite films, which are suppressed in 1D/3D perovskite films. It has been accepted widely that the metallic lead clusters (Pb 0 ) can form deep defects and trap the free carriers in perovskite films, leading to a severe nonradiative recombination and a deteriorate of device performance and long term stability.…”

“…Figure 2c displays the J-V curves with different scan directions, showing a V oc , J sc , FF, and PCE of 0.99 V, 3.76 mA cm À2 , 0.56, and 2.09%, respectively, without hysteresis, which is higher than some previous reports using pure 1D perovskite materials as the sensitizers as summarized in Table S1, Supporting Information. [9] However, low efficiency of Me 3 SPbI 3 based solar cell could be attributed to the rough and porous nature of the perovskite film and the relatively narrow absorption range up to around 530 nm compared with other typical 3D perovskite such as MAPbI 3 or FAPbI 3. [32,37] It was a challenge for the preparation of an uniform and homogeneous film due to the large tolerance factor in1D crystal structures [34,37] obtained via two-step solution process.…”

“…[ 31 ] Very recently, Bi et al employed 2‐diethylaminoethylchloride hydrochloride (DEAECCl) to prepare a novel 1D perovskitoid, which can induce the growth of 1D@3D perovskite structure, leading to better crystallinity and charge transport, and reduced remnant tensile strain in 3D perovskite film, thereby enhance the PCE and stability of the devices. [ 9 ] However, steric hindrance induced by large organic cation in 1D perovskite leads to poor and anisotropic charge conductivity resulting lower PCE value. Thus, further research is needed to explore new organic cation leading to 1D perovskite structure which can be synchronized with 3D perovskite.…”

“…[6][7][8] However, because of their intrinsic structural characteristics, 3D perovskites still suffer from poor stability in ambient conditions, when exposed to UV light, moisture, heat, and electric field, which limits the commercialization potential of the PSCs. [9][10][11][12][13] To address the longterm stability issue, 1D perovskites are emerging as ideal alternatives due to their structural diversity, tunable optical properties, and superior environmental stability. [14][15][16] From the molecular level, the 1D perovskites, are different from the morphological 1D nanowires, nanofibers, and nanorods.…”