Surface reaction for efficient and stable inverted perovskite solar cells

Low-dimensional (LD) perovskites can effectively passivate and stabilize 3D perovskites for high-performance perovskite solar cells (PSCs). Regards CsPbI3-based PSCs, the influence of high-temperature annealing on the LD perovskite passivation effect has to be taken into account due to fact the black-phase CsPbI3 crystallization requires high-temperature treatment, however, which has been rarely concerned so far. Here, the thermal stability of LD perovskites based on three hydrophobic organic ammonium salts and their passivation effect toward CsPbI3 and the whole device performance, have been investigated. It is found that, phenyltrimethylammonium iodide (PTAI) and its corresponding LD perovskites exhibit excellent thermal stability. Further investigation reveals that PTAI-based LD perovskites are mainly distributed at grain boundaries, which not only enhances the phase stability of CsPbI3 but also effectively suppresses non-radiative recombination. As a consequence, the champion PSC device based on CsPbI3 exhibits a record efficiency of 21.0 % with high stability. 

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

Perovskite solar cells (PSCs) have made incredibly fast progress in past years, pushing the efficiency approaching 26%, which is comparable to the best silicon solar cells. One of the features...

High Open-circuit Voltage of Perovskite Solar Cells: A Review

All-inorganic CsPbI3 perovskite presents preeminent chemical stability and desirable band gap as the front absorber for perovskite/silicon tandem solar cells. Unfortunately, CsPbI3 perovskite solar cells (PSCs) still show low efficiency due to high density of defects in solution-prepared CsPbI3 films. Herein, three kinds of hydrazine derivatives (benzoyl hydrazine (BH), formohydrazide (FH) and benzamide (BA)) are designed to reduce the defect density and stabilize the phase of CsPbI3 . Calculation and characterization results corroborate that the carboxyl and hydrazine groups in BH form strong chemical bonds with Pb2+ ions, resulting in synergetic double coordination. In addition, the hydrazine group in the BH also forms a hydrogen bond with iodine to assist the coordination. Consequently, a high efficiency of 20.47% is achieved, which is the highest PCE among all pure CsPbI3-based PSCs reported to date. In addition, an unencapsulated device showed excellent stability in ambient air.

Hydrazide Derivatives for Defect Passivation in Pure CsPbI3 Perovskite Solar Cells.

PbS/CdS heterojunction thin layer affords high-performance carbon-based all-inorganic solar cells

In halide perovskite solar cells the formation of secondary-phase excess lead iodide (PbI2) has some positive effects on power conversion efficiency (PCE) but can be detrimental to device stability and lead to large hysteresis effects in voltage sweeps. We converted PbI2 into an inactive (PbI2)2RbCl compound by RbCl doping, which effectively stabilizes the perovskite phase. We obtained a certified PCE of 25.6% for FAPbI3 (FA, formamidinium) perovskite solar cells on the basis of this strategy. Devices retained 96% of their original PCE values after 1000 hours of shelf storage and 80% after 500 hours of thermal stability testing at 85°C. Description Managing excess lead iodide In hybrid perovskite solar cells, the formation of lead iodide (PbI2) can provide some passivation effects but can lead to device instability and hysteresis in current–density changes with voltage. Zhao et al. show that doping with rubidium chloride (RbCl) can create a passive inactive (PbI2)2RbCl phase that stabilizes the perovskite phase and lowers its bandgap. Devices exhibited 25.6% certified power efficiency and maintained 80% of that efficiency after 500 hours of operation at 85°C. —PDS Converting PbI2 into inactive (PbI2)2RbCl by RbCl doping can stabilize the perovskite phase and increase efficiency.

Inactive (PbI2)2RbCl stabilizes perovskite films for efficient solar cells

Cesium lead iodide (CsPbI3 ) perovskite has gained great attention due to its potential thermal stability and appropriate bandgap (≈1.73 eV) for tandem cells. However, the moisture-induced thermodynamically unstable phase and large open-circuit voltage (VOC ) deficit and also the low efficiency seriously limit its further development. Herein, long chain phenylethylammonium (PEA) is utilized into CsPbI3 perovskite to stabilize the orthorhombic black perovskite phase (γ-CsPbI3 ) under ambient condition. Furthermore, the moderate lead acetate (Pb(OAc)2 ) is controlled to combine with phenylethylammonium iodide to form the 2D perovskite, which can dramatically suppress the charge recombination in CsPbI3 . Unprecedentedly, the resulted CsPbI3 solar cells achieve a 17% power conversion efficiency with a record VOC of 1.33 V, the VOC deficit is only 0.38 V, which is close to those in organic-inorganic perovskite solar cells (PSCs). Meanwhile, the PEA modified device maintains 94% of its initial efficiency after exceeding 2000 h of storage in the low-humidity controlled environment without encapsulation.

Stabilizing γ-CsPbI3 Perovskite via Phenylethylammonium for Efficient Solar Cells with Open-Circuit Voltage over 1.3 V.

Updated Progresses in Perovskite Solar Cells


 Perovskite solar cells (PSCs) has witnessed great achievement in the past ten years. Most of previous research are focus on the n-i-p structure of PSCs with ultra-high efficiency. While the n-i-p devices usually used the unstable charge transport layers, such as the hygroscopic doped spiro-OMeTAD, which affect the long-term stability. The inverted device with the p-i-n structure owns better stability while using stable undoped organic molecular or metal oxide materials. There are significant progresses in inverted PSCs, most of them related to charge transport or interface engineering. In this review, we will mainly summarize the inverted PSCs progresses related to the interface engineering. After that, we prospect the future direction on inverted PSCs.

Recent Advances of Interface Engineering in Inverted Perovskite Solar Cells

Simple Summary It is well known that brooding temperature affects yolk sac absorption so as to affect the growth and development of geese. In order to explore the brooding temperature on the absorption of yolk sac and the ovary development of goslings, the weight and fatty acid composition of yolk sac, body weight, ovary weight and structure was measured. The expression of ovary development related genes was quantified. The results suggested that 29 °C brooding temperature in the early stage could promote the absorption of fatty acids from yolk sac, which is conducive to ovary and body weight, and the expression of ovarian development-related genes of CHK1, FGF12, and SMAD4. The results could provide guidance on gosling brooding for farmers. Abstract In order to explore the brooding temperature on the absorption of yolk sac and the ovary development of goslings, 126 1-day-old female goslings were randomly divided into three groups with three replicates in each group. The brooding temperatures were set at 32 °C, 29 °C and 26 °C (represent G32, G29 and G26), respectively, in each group. At 48, 60 and 72 h, two goslings from each replicate were weighed, and the yolk sac was collected and weighed. The fatty acid composition of yolk sac fluid was determined by gas chromatography-mass spectrometry (GC-MS). At 1, 2, 3, and 4 weeks of age, goslings from each replicate were weighed, the ovaries were weighed and fixed for hematoxylin-eosin (HE) staining, Cell cycle checkpoint kinase 1 (CHK1), fibroblast growth factor 12 (FGF12) and Sma-and Mad-related protein 4 (SMAD4) which related to regulation of ovarian development were determined by qRT-PCR. The body weight of G29 and G26 was significantly higher than that of G32 at 72 h (p < 0.05). The contents of C14:0, C16:0, C18:2n6c and total fatty acid (ΣTFA) from G32 were significantly higher than that of G26 (p < 0.05), and the contents of C18:1n9t and C22:0 in G29 were significantly higher than that of G26 (p < 0.05). The ovary index, ovary and body weight were significantly higher in G29 than those of G32 and G26 at 2 weeks of age (p < 0.05). The number of primordial follicles, number of primary follicles and diameter of primary follicles were significantly higher in G29 than those in G32 and G26 at 4 weeks of age (p < 0.05). In G29, the expression of CHK1 and SMAD4 was significantly higher than that in G32, and the expression of FGF12 and SMAD4 was significantly higher (p < 0.05) than that in G26 at 2 and 4 weeks of age. In conclusion, brooding temperature at 29 °C could promote the absorption of fatty acids in yolk sac, body weight gain, and ovarian development through up-regulating the expression of CHK1, FGF12 and SMAD4.

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Shiqi Yu

Papers

Inactive (PbI2)2RbCl stabilizes perovskite films for efficient solar cells

Stabilizing γ-CsPbI3 Perovskite via Phenylethylammonium for Efficient Solar Cells with Open-Circuit Voltage over 1.3 V.

Updated Progresses in Perovskite Solar Cells

Recent Advances of Interface Engineering in Inverted Perovskite Solar Cells

Brooding Temperature Alters Yolk Sac Absorption and Affected Ovarian Development in Goslings