Unveiling the Potential of Ambient Air Annealing for Highly Efficient Inorganic CsPbI3 Perovskite Solar Cells

Here, we report a detailed surface analysis of dry- and ambient air-annealed CsPbI3 films and their subsequent modified interfaces in perovskite solar cells. We revealed that annealing in ambient air does not adversely affect the optoelectronic properties of the semiconducting film; instead, ambient air-annealed samples undergo a surface modification, causing an enhancement of band bending, as determined by hard X-ray photoelectron spectroscopy measurements. We observe interface charge carrier dynamics changes, improving the charge carrier extraction in CsPbI3 perovskite solar cells. Optical spectroscopic measurements show that trap state density is decreased due to ambient air annealing. As a result, air-annealed CsPbI3-based n-i-p structure devices achieved a 19.8% power conversion efficiency with a 1.23 V open circuit voltage.

Minimizing Interfacial Recombination in 1.8 eV Triple-Halide Perovskites for 27.5% Efficient All-Perovskite Tandems

All-perovskite tandem solar cells show great potential to enable the highest performance at reasonable costs for a viable market entry in the near future. In particular, wide-bandgap (WBG) perovskites with higher open-circuit voltage (VOC ) are essential to further improve the tandem solar cells' performance. Here, a new 1.8 eV bandgap triple-halide perovskite composition in conjunction with a piperazinium iodide (PI) surface treatment is developed. With structural analysis, it is found that the PI modifies the surface through a reduction of excess lead iodide in the perovskite and additionally penetrates the bulk. Constant light-induced magneto-transport measurements are applied to separately resolve charge carrier properties of electrons and holes. These measurements reveal a reduced deep trap state density, and improved steady-state carrier lifetime (factor 2.6) and diffusion lengths (factor 1.6). As a result, WBG PSCs achieve 1.36 V VOC , reaching 90% of the radiative limit. Combined with a 1.26 eV narrow bandgap (NBG) perovskite with a rubidium iodide additive, this enables a tandem cell with a certified scan efficiency of 27.5%.

Poly(3-hexylthiophene)/perovskite Heterointerface by Spinodal Decomposition Enabling Efficient and Stable Perovskite Solar Cells

The best research-cell efficiency of perovskite solar cells (PSCs) is comparable with that of mature silicon solar cells (SSCs); However, the industrial development of PSCs lags far behind SSCs. PSC is a multiphase and multicomponent system, whose consequent interfacial energy loss and carrier loss seriously affect the performance and stability of devices. Here, by using spinodal decomposition, a spontaneous solid phase segregation process, in situ introduces a poly(3-hexylthiophene)/perovskite (P3HT/PVK) heterointerface with interpenetrating structure in PSCs. The P3HT/PVK heterointerface tunes the energy alignment, thereby reducing the energy loss at the interface; The P3HT/PVK interpenetrating structure bridges a transport channel, thus decreasing the carrier loss at the interface. The simultaneous mitigation of energy and carrier losses by P3HT/PVK heterointerface enables n-i-p geometry device a power conversion efficiency of 24.53% (certified 23.94%) and excellent stability. These findings demonstrate an ingenious strategy to optimize the performance of PSCs by heterointerface via Spinodal decomposition.

Resolving electron and hole transport properties in semiconductor materials by constant light-induced magneto transport

The knowledge of minority and majority charge carrier properties enables controlling the performance of solar cells, transistors, detectors, sensors, and LEDs. Here, we developed the constant light induced magneto transport method which resolves electron and hole mobility, lifetime, diffusion coefficient and length, and quasi-Fermi level splitting. We demonstrate the implication of the constant light induced magneto transport for silicon and metal halide perovskite films. We resolve the transport properties of electrons and holes predicting the material's effectiveness for solar cell application without making the full device. The accessibility of fourteen material parameters paves the way for in-depth exploration of causal mechanisms limiting the efficiency and functionality of material structures. To demonstrate broad applicability, we further characterized twelve materials with drift mobilities spanning from 10-3 to 103 cm2V-1s-1 and lifetimes varying between 10-9 and 10-3 seconds. The universality of our method its potential to advance optoelectronic devices in various technological fields.

Interface Modification for Energy Level Alignment and Charge Extraction in CsPbI3 Perovskite Solar Cells

In perovskite solar cells (PSCs) energy level alignment and charge extraction at the interfaces are the essential factors directly affecting the device performance. In this work, we present a modified interface between all-inorganic CsPbI3 perovskite and its hole-selective contact (spiro-OMeTAD), realized by the dipole molecule trioctylphosphine oxide (TOPO), to align the energy levels. On a passivated perovskite film, with n-octylammonium iodide (OAI), we created an upward surface band-bending at the interface by TOPO treatment. This improved interface by the dipole molecule induces a better energy level alignment and enhances the charge extraction of holes from the perovskite layer to the hole transport material. Consequently, a Voc of 1.2 V and a high-power conversion efficiency (PCE) of over 19% were achieved for inorganic CsPbI3 perovskite solar cells. Further, to demonstrate the effect of the TOPO dipole molecule, we present a layer-by-layer charge extraction study by a transient surface photovoltage (trSPV) technique accomplished by a charge transport simulation.

Stabilization of Inorganic Perovskite Solar Cells with a 2D Dion-Jacobson Passivating Layer

Inorganic metal halide perovskites such as CsPbI3 are promising for high-performance, reproducible, and robust solar cells. However, inorganic perovskites are sensitive to humidity, which causes the transformation from the black phase to the yellow δ, non-perovskite phase. Such phase instability has been a significant challenge to long-term operational stability. Here, a surface dimensionality reduction strategy is reported, using 2-(4-aminophenyl)ethylamine cation to construct a Dion-Jacobson 2D phase that covers the surface of the 3D inorganic perovskite structure. The Dion-Jacobson layer mainly grows at the grain boundaries of the perovskite, effectively passivating surface defects and providing favourable interfacial charge transfer. The resulting inorganic perovskite films exhibit excellent humidity resistance when submerged in an aqueous solution (isopropanol:water = 4:1 v/v) and exposed to a 50% humidity air atmosphere. The Dion-Jacobson 2D/3D inorganic perovskite solar cell (PSC) achieves a power conversion efficiency (PCE) of 19.5% with a Voc of 1.197 eV. It retains 83% of its initial PCE after 1260 h of maximum power point tracking under 1.2 sun illumination. The work demonstrates an effective way for stabilizing efficient inorganic perovskite solar cells.

Managing Excess Lead Iodide with Functionalized Oxo-Graphene Nanosheets for Stable Perovskite Solar Cells

Stability issues could prevent lead halide perovskite solar cells (PSCs) from commercialization despite it having a comparable power conversion efficiency (PCE) to silicon solar cells. Overcoming drawbacks affecting their long-term stability is gaining incremental importance. Excess lead iodide (PbI2 ) causes perovskite degradation, although it aids in crystal growth and defect passivation. Herein, we synthesized functionalized oxo-graphene nanosheets (Dec-oxoG NSs) to effectively manage the excess PbI2 . Dec-oxoG NSs provide anchoring sites to bind the excess PbI2 and passivate perovskite grain boundaries, thereby reducing charge recombination loss and significantly boosting the extraction of free electrons. The inclusion of Dec-oxoG NSs leads to a PCE of 23.7 % in inverted (p-i-n) PSCs. The devices retain 93.8 % of their initial efficiency after 1,000 hours of tracking at maximum power points under continuous one-sun illumination and exhibit high stability under thermal and ambient conditions.

Interface engineering for high-performance, triple-halide perovskite-silicon tandem solar cells

Improved stability and efficiency of two-terminal monolithic perovskite-silicon tandem solar cells will require reductions in recombination losses. By combining a triple-halide perovskite (1.68 electron volt bandgap) with a piperazinium iodide interfacial modification, we improved the band alignment, reduced nonradiative recombination losses, and enhanced charge extraction at the electron-selective contact. Solar cells showed open-circuit voltages of up to 1.28 volts in p-i-n single junctions and 2.00 volts in perovskite-silicon tandem solar cells. The tandem cells achieve certified power conversion efficiencies of up to 32.5%.

What is special about Y6; the working mechanism of neat Y6 organic solar cells

Non-fullerene acceptors (NFAs) have delivered advancement in bulk heterojunction organic solar cell efficiencies, with a significant milestone of 20% now in sight. However, these materials challenge the accepted wisdom of how organic solar cells work. In this work we present a neat Y6 device with an efficiency above 4.5%. We thoroughly investigate mechanisms of charge generation and recombination as well as transport in order to understand what is special about Y6. Our data suggest that Y6 generates bulk free charges, with ambipolar mobility, which can be extracted in the presence of transport layers.

Pyridine Controlled Tin Perovskite Crystallization

Controlling the crystallization of perovskite in a thin film is essential in making solar cells. Processing tin-based perovskite films from solution is challenging because of the uncontrollable faster crystallization of tin than the most used lead perovskite. The best performing devices are prepared by depositing perovskite from dimethyl sulfoxide because it slows down the assembly of the tin-iodine network that forms perovskite. However, while dimethyl sulfoxide seems the best solution to control the crystallization, it oxidizes tin during processing. This work demonstrates that 4-(tert-butyl) pyridine can replace dimethyl sulfoxide to control the crystallization without oxidizing tin. We show that tin perovskite films deposited from pyridine have a 1 order of magnitude lower defect density, which promotes charge mobility and photovoltaic performance.

AB0986 RISK OF SARCOPENIA IN THE WOMEN WITH OSTEOARTHRITIS

Background

Recently, physicians all over the world have been focusing on the relationship between sarcopenia and osteoarthritis (OA) [1, 2]. This connection is considered from different positions: as coexisting conditions, sarcopenia as a risk factor for the progression of OA, or OA as a risk factor for sarcopenia.

Objectives

The aim of this study was to determine the risk of sarcopenia (according to the SARC-F Questionnaire) and the level of probable sarcopenia in Ukrainian women with (hip and knee) OA.

Methods

The study included 271 women aged 50-84 years old (mean age 65.6 ±8.0 years, mean height 162.2±5.6, mean body weight 76.7±14.2, mean BMI 29.1±5.1). All subjects were divided into 2 groups: the group of healthy women (group I, n=176), a group of patients with hip or knee osteoarthritis (OA) (group II, n=95). The risk of sarcopenia was determined by the SARC-F Questionnaire. The probable sarcopenia was determined due to muscles strength (handgrip strength using spring hand dynamometer ≤ 16(kg)) and physical performance (5-time chair stand test > 15 s), the fall risk – by Desmond Fall Risk Questionnaires and function – according to the assessment of IADL scale.

Results

In 20.3% of females without musculoskeletal pathology and in 34.7% of women with OA was detected high risk of sarcopenia. The probable sarcopenia was practically 2 times higher in patients with OA and was equal to 42.1% compared to 21.5% in healthy women. According to the Desmond Fall Risk Questionnaire, 27.5% of healthy subjects and 49.3% with OA had increased fall risk. Low function (according to the assessment of the IADL scale) was detected in 36.4% of females without pathology of the musculoskeletal system and in 57.2% of women with OA.

Conclusion

Our results demonstrated that the incidence of probable sarcopenia was 2 times higher in women with hip and knee OA, as well as the risk of sarcopenia – 34.7%, compared to healthy subjects – 20.3%. Also, the risk of falls and the need for outside help were higher in patients with hip and knee OA but their function (by IADL scale) was significantly lower.

References

[1]Amirthalingam H., Cicuttini F. M., Wang Y. et al. (2019). Association between sarcopenia and osteoarthritis-related knee structural changes: a systematic review. Osteoarthritis and Cartilage, 27, S472. doi:10.1016/j.joca.2019.02.515.

[2]Jin W. S., Choi E. J., Lee S. Y. et al. (2017). Relationships among Obesity, Sarcopenia, and Osteoarthritis in the Elderly. Journal of Obesity & Metabolic Syndrome, 26(1), 36–44. doi:10.7570/jomes.2017.26.1.36.

Disclosure of Interests

None declared

AB1127 ANTIOSTEOPOROTIC TREATMENT AND COVID-19 RISK: IS THERE AN ASSOCIATION?

Background

Nowadays, the COVID-19 and its complications are considered an important medical issue with aggravated medico-social outcomes, both at the worldwide scale, and in terms of various individual countries. Despite the recent ASBMR, AACE, Endocrine Society, ECTS and NOF recommendations according to osteoporosis management in the era of COVID-19 the influence of antiosteoporotic drugs on disease incidence and severity continue to be studied [1, 2].

Objectives

The purpose of this study was to assess the COVID-19 risk for the patients receiving the parenteral bisphosphonate or Denosumab treatment, and the severity of its course in the systemic osteoporosis patients.

Methods

We performed the phone survey and studied the results of 195 patients (92 % women; mean age – 62.7±10.8 years, height – 161.0±8.0 cm, body weight – 68.9±12.3 kg) with systemic osteoporosis depending on the current use of parenteral antiresorptive drugs (Zoledronic acid, Ibandronic acid, or Denosumab, n=125) and compared the results with patients with osteoporosis who did not use any antiosteoporotic drugs previously (n=70). The mean duration of antiosteoporotic treatment did not vary across the groups, accounting for 15 [9-27] months. Prior to the beginning of the antiosteoporotic therapy, all the patients had a confirmed diagnosis of osteoporosis at the Ukrainian scientific-medical Center of osteoporosis.

Results

We did not reveal any significant differences in the COVID-19 frequency and severity depending on the presence and type of parenteral antiosteoporotic therapy. Additionally, there were no differences depending on patients’ age of sex, obesity presence, and other osteoporosis risk factors. The risk of COVID-19 in the patients with systemic osteoporosis did not differ depending on antiresorptive drug use, amounting (Odd Ratio (OR) 95 % CI) to 1.1 (0.6-2.0), or on the use of the definite antiosteoporotic drug (for the Zoledronic acid - 0.9 (0.4-2.0), the Ibandronic acid - 1.1 (0.5-2.3), and for the Denosumab - 1.6 (0.5-5.2).

Conclusion

Our study did not reveal any significant differences in the COVID-19 frequency and severity depending on the presence and type of parenteral antiosteoporotic therapy. We conclude that parenteral antiosteoporotic drugs (Zoledronic acid, Ibandronic acid, or Denosumab) do not have an influence on COVID-19 frequency and severity and can be recommended for the continuation of treatment of patients with osteoporosis.

References

[1]Joint Guidance on Osteoporosis Management in the Era of COVID-19 from the ASBMR, AACE, Endocrine Society, ECTS & NOF. https://www.asbmr.org/about/statement-detail/joint-guidance-on-osteoporosis-management-covid-19.

[2]Blanch-Rubió J, Soldevila-Domenech N, Tío L, et al (2020) Influence of anti-osteoporosis treatments on the incidence of COVID-19 in patients with non-inflammatory rheumatic conditions. Aging (Albany NY). 12(20):19923-19937. doi:10.18632/aging.104117.

Disclosure of Interests

None declared

Deciphering the effect of traps on electronic charge transport properties of methylammonium lead tribromide perovskite

Halide perovskites have undergone remarkable developments as highly efficient optoelectronic materials for a variety of applications. Several studies indicated the critical role of defects on the performance of perovskite devices. However, the parameters of defects and their interplay with free charge carriers remain unclear. In this study, we explored the dynamics of free holes in methylammonium lead tribromide (MAPbBr₃) single crystals using the time-of-flight (ToF) current spectroscopy. By combining ToF spectroscopy and Monte Carlo simulation, three energy states were detected in the bandgap of MAPbBr₃ In addition, we found the trapping and detrapping rates of free holes ranging from a few microseconds to hundreds of microseconds. Contrary to previous studies, we revealed a strong detrapping activity of traps. We showed that these traps substantially affect the transport properties of MAPbBr₃, including mobility and mobility-lifetime product. Our results provide an insight on charge transport properties of perovskite semiconductors.

Charge Sharing in (CdZn)Te Pixel Detector Characterized by Laser-Induced Transient Currents

Performance of the (CdZn)Te pixelated detectors heavily relies on the quality of the underlying material. Modern laser-induced transient current technique addresses this problem as a convenient tool for characterizing the associated charge distribution. In this paper, we investigated the charge sharing phenomenon in (CdZn)Te pixel detector as a function of the charge collected on adjacent pixels. The current transients were generated in the defined 4 mm² spots using 660 nm laser illumination. Waveforms measured on the pixel of interest and its surroundings were used to build the maps of the collected charge at different biases. The detailed study of the maps allowed us to distinguish the charge sharing region, the region with a defect, and the finest part in terms of the performance part of the pixelated anode. We observed the principal inhomogeneity complicating the assignment of the illuminated spot to the nearest pixel.

Differential single-pixel camera enabling low-cost microscopy in near-infrared spectral region

The optical microscope for wavelengths above 1100 nm is a very important tool for characterizing the microstructure of a broad range of samples. The availability of the technique is, however, limited because special detectors with temperature stabilization, which are costly, must be used. We present the construction of a low-cost near-infrared microscope (800-1700 nm) based on the principles of compressed sensing. The presented setup is very simple and robust. It requires no temperature stabilization and can be used under standard laboratory conditions. We demonstrate that such a microscope, which uses a simple pair of balanced photodiodes as a detector, can acquire microscopic images of the sample that are comparable with those acquired by a standard microscope. Owing to its simplicity, the presented setup can provide access to infrared transmission microscopy and to a broad range of laboratories.