High-Efficiency Perovskite Solar Cells Kim, Jin Young; Lee, Jin-Wook; Jung, Hyun Suk ...
Chemical reviews,
08/2020, Volume:
120, Issue:
15
Journal Article
Peer reviewed
With rapid progress in a power conversion efficiency (PCE) to reach 25%, metal halide perovskite-based solar cells became a game-changer in a photovoltaic performance race. Triggered by the ...development of the solid-state perovskite solar cell in 2012, intense follow-up research works on structure design, materials chemistry, process engineering, and device physics have contributed to the revolutionary evolution of the solid-state perovskite solar cell to be a strong candidate for a next-generation solar energy harvester. The high efficiency in combination with the low cost of materials and processes are the selling points of this cell over commercial silicon or other organic and inorganic solar cells. The characteristic features of perovskite materials may enable further advancement of the PCE beyond those afforded by the silicon solar cells, toward the Shockley–Queisser limit. This review summarizes the fundamentals behind the optoelectronic properties of perovskite materials, as well as the important approaches to fabricating high-efficiency perovskite solar cells. Furthermore, possible next-generation strategies for enhancing the PCE over the Shockley–Queisser limit are discussed.
Thin-film transistor (TFT)-driven full-color organic light-emitting diodes (OLEDs) with vertically stacked structures are developed herein using photolithography processes, which allow for ...high-resolution displays of over 2,000 pixels per inch. Vertical stacking of OLEDs by the photolithography process is technically challenging, as OLEDs are vulnerable to moisture, oxygen, solutions for photolithography processes, and temperatures over 100 °C. In this study, we develop a low-temperature processed Al
O
/SiN
bilayered protection layer, which stably protects the OLEDs from photolithography process solutions, as well as from moisture and oxygen. As a result, transparent intermediate electrodes are patterned on top of the OLED elements without degrading the OLED, thereby enabling to fabricate the vertically stacked OLED. The aperture ratio of the full-color-driven OLED pixel is approximately twice as large as conventional sub-pixel structures, due to geometric advantage, despite the TFT integration. To the best of our knowledge, we first demonstrate the TFT-driven vertically stacked full-color OLED.
Graphene leading to high surface‐to‐volume ratio and outstanding conductivity is applied for gas molecule sensing with fully utilizing its unique transparent and flexible functionalities which cannot ...be expected from solid‐state gas sensors. In order to attain a fast response and rapid recovering time, the flexible sensors also require integrated flexible and transparent heaters. Here, large‐scale flexible and transparent gas molecule sensor devices, integrated with a graphene sensing channel and a graphene transparent heater for fast recovering operation, are demonstrated. This combined all‐graphene device structure enables an overall device optical transmittance that exceeds 90% and reliable sensing performance with a bending strain of less than 1.4%. In particular, it is possible to classify the fast (≈14 s) and slow (≈95 s) response due to sp2‐carbon bonding and disorders on graphene and the self‐integrated graphene heater leads to the rapid recovery (≈11 s) of a 2 cm × 2 cm sized sensor with reproducible sensing cycles, including full recovery steps without significant signal degradation under exposure to NO2 gas.
Flexible and transparent molecule sensor integrated with a graphene sensing channel and a graphene transparent heater allows us to a high optical transmittance (>90%) and reliable sensing performance under a bending strain (≈1.4%). The self‐integrated graphene heater leads to the rapid recovery (≈11 s) of a centimeter sized sensor with full recovery steps without signal degradation.
Colloidal quantum dots (QDs) stand at the forefront of a variety of photonic applications given their narrow spectral bandwidth and near-unity luminescence efficiency. However, integrating ...luminescent QD films into photonic devices without compromising their optical or transport characteristics remains challenging. Here we devise a dual-ligand passivation system comprising photocrosslinkable ligands and dispersing ligands to enable QDs to be universally compatible with solution-based patterning techniques. The successful control over the structure of both ligands allows the direct patterning of dual-ligand QDs on various substrates using commercialized photolithography (i-line) or inkjet printing systems at a resolution up to 15,000 pixels per inch without compromising the optical properties of the QDs or the optoelectronic performance of the device. We demonstrate the capabilities of our approach for QD-LED applications. Our approach offers a versatile way of creating various structures of luminescent QDs in a cost-effective and non-destructive manner, and could be implemented in nearly all commercial photonics applications where QDs are used.
Excellent color purity with a tunable band gap renders organic–inorganic halide perovskite highly capable of performing as light-emitting diodes (LEDs). Perovskite nanocrystals show a ...photoluminescence quantum yield exceeding 90%, which, however, decreases to lower than 20% upon formation of a thin film. The limited photoluminescence quantum yield of a perovskite thin film has been a formidable obstacle for development of highly efficient perovskite LEDs. Here, we report a method for highly luminescent MAPbBr3 (MA = CH3NH3) nanocrystals formed in situ in a thin film based on nonstoichiometric adduct and solvent-vacuum drying approaches. Excess MABr with respect to PbBr2 in precursor solution plays a critical role in inhibiting crystal growth of MAPbBr3, thereby forming nanocrystals and creating type I band alignment with core MAPbBr3 by embedding MAPbBr3 nanocrystals in the unreacted wider band gap MABr. A solvent-vacuum drying process was developed to preserve nanocrystals in the film, which realizes a fast photoluminescence lifetime of 3.9 ns along with negligible trapping processes. Based on a highly luminescent nanocrystalline MAPbBr3 thin film, a highly efficient green LED with a maximum external quantum efficiency of 8.21% and a current efficiency of 34.46 cd/A was demonstrated.
•IRB/AML fixed-dose regimens show superior antihypertensive efficacy over IRB monotherapy.•A potential benefit of IRB/AML regimens was noted in the elderly and T2DM patients.•IRB/AML combinations are ...well-tolerated and have comparable safety to IRB monotherapy.
This study aimed to evaluate the efficacy and tolerability of irbesartan (IRB) and amlodipine (AML) combination therapy in patients with essential hypertension whose blood pressure (BP) was not controlled by IRB monotherapy.
Two multicenter, randomized, double-blind, placebo-controlled, phase III studies were conducted in Korea (the I-DUO 301 study and the I-DUO 302 study). After a 4-week run-in period with either 150 mg IRB (I-DUO 301 study) or 300 mg IRB (I-DUO 302 study), patients with uncontrolled BP (ie, mean sitting systolic BP MSSBP ≥140 mmHg to <180 mmHg and mean sitting diastolic BP <110 mmHg) were randomized to the placebo, AML 5 mg, or AML 10 mg group. A total of 428 participants were enrolled in the 2 I-DUO studies. In the I-DUO 301 study, 271 participants were randomized in a 1:1:1 ratio to receive either IRB/AML 150/5 mg, IRB/AML 150/10 mg, or IRB 150 mg/placebo. In the I-DUO 302 study, 157 participants were randomized in a 1:1 ratio to receive IRB/AML 300/5 mg or IRB 300 mg/placebo. The primary endpoint was the change in MSSBP from baseline to week 8. Tolerability was assessed according to the development of treatment-emergent adverse events (TEAEs) and clinically significant changes in physical examination, laboratory tests, pulse, and 12-lead electrocardiography.
In I-DUO 301, the mean (SD) changes of MSSBP at week 8 from baseline were −14.78 (12.35) mmHg, −21.47 (12.78) mmHg, and −8.61 (12.19) mmHg in the IRB/AML 150/5 mg, IRB/AML 150/10 mg, and IRB 150 mg/placebo groups, respectively. In I-DUO 302, the mean (SD) changes of MSSBP at week 8 from baseline were −13.30 (12.47) mmHg and −7.19 (15.37) mmHg in the IRB/AML 300/5 mg and IRB 300 mg/placebo groups, respectively. In both studies, all combination groups showed a significantly higher reduction in MSSBP than the IRB monotherapy groups (P < 0.001 for both). TEAEs occurred in 10.00%, 10.99%, and 12.22% of participants in the IRB/AML 150/5 mg, IRB/AML 150/10 mg, and IRB 150 mg/placebo groups, respectively, in I-DUO 301 and in 6.33% and 10.67% of participants in the IRB/AML 300/5 mg and IRB 300 mg/placebo groups, respectively, in I-DUO 302, with no significant between-group differences. Overall, there was one serious adverse event throughout I-DUO study.
The combination of IRB and AML has superior antihypertensive effects compared with IRB alone over an 8-week treatment period, with placebo-like tolerability.
ClinicalTrials.gov identifier: NCT05476354 (I-DUO 301), NCT05475665 (I-DUO 302).
We investigated the efficacy and safety of liraglutide 3 mg daily in combination with diet and exercise 2, 4, and 6 months after initiation in real-world settings in Korea.
People first using ...liraglutide starting in 2018 were recruited from ten sites in Korea. Body weight and body mass index (BMI) were measured after 2, 4, and 6 months and compared with baseline values.
The full cohort comprised 769 participants: 672 in the 2-month group, 427 in the 4-month group, and 219 in the 6-month group. The baseline mean ± standard deviation of BMI and body weight were 32.2 ± 5.1 kg/m
, and 87.5 ± 18.8 kg, respectively. Body weight and BMI decreased after initiation of liraglutide treatment: -2.94 kg and -1.08 kg/m
at 2 months; -4.23 kg and -1.55 kg/m
at 4 months, and -5.14 kg and -1.89 kg/m
at 6 months (all P < 0.001). In the 6-month cohort, 52.5% and 18.3% of subjects lost ≥5% and ≥10% of body weight, respectively. After 6 months, systolic and diastolic blood pressure decreased significantly by 3.90 and 1.93 mmHg, respectively. In those with diabetes mellitus, HbA1c and fasting glucose levels decreased significantly by 1.14% and 27.8 mg/dl, respectively. Among all participants, 27.6% experienced adverse effects, including nausea (20.8%), vomiting (5.2%), diarrhoea (2.5%), and skin rash (3.6%). Documented reasons for discontinuation of treatment were lack of effect (4.4%), adverse events (4.3%), and high cost (3.1%).
In real-world settings in Korea, daily treatment with liraglutide 3 mg was associated with clinically meaningful weight loss without serious adverse events.
Background and Aim
Coexistent gastrointestinal symptom profiles and prevalence or associated factors for the overlap between each functional dyspepsia (FD) and irritable bowel syndrome (IBS) group ...remain unclear. Thus, the aim of the present study was to evaluate the clinicodemographic features of FD, IBS, and IBS‐FD overlap and assess the risk factors thereof, including subtype and genetic polymorphisms for IBS‐FD.
Methods
Consecutive patients were enrolled from the outpatient Gastroenterology clinics of Bundang Seoul National University Hospitals in Korea. All gastrointestinal symptoms occurring at least once per week in the previous 3 months were recorded. Diagnostic criteria of functional gastrointestinal disorders were based on the Rome III criteria. Risk factors including genetic polymorphisms of 5‐HTTLPR and ADRA2A 1291 G alleles and CCK‐1R intron 779T>C were assessed using a multivariate logistic regression model.
Results
A total of 632 subjects (278 control subjects, 308 FD, 156 IBS, and 110 who met the criteria for both FD and IBS) were included in this study. Patients with IBS‐FD overlap had more severe symptoms (such as bloating, nausea, vomiting, hard or lumpy stools, defecation straining, and a feeling of incomplete bowel movement) and higher depression scores compared with non‐overlap patients. Single/divorced or widowed marital status, nausea, bloating, and a feeling of incomplete emptying after bowel movements were independent risk factors for IBS‐FD overlap among IBS patients. In contrast, young age, depression, bloating, and postprandial distress syndrome were positively associated with IBS‐FD overlap among FD patients. 5‐HTTLPR L/L was a risk factor for the co‐occurrence of IBS‐C among FD patients (OR: 12.47; 95% CI: 2.00–77.75; P = 0.007).
Conclusions
Bloating was a risk factor for IBS‐FD overlap. Patients with postprandial distress syndrome have a higher risk of coexisting IBS, particularly constipation‐dominant IBS.
Zeolites are potentially a more robust desalination alternative as they are chemically stable and possess the essential properties needed to reject ions. This work proposes to use zeolite membranes ...for desalination of saline recycled wastewater for the possibility of avoiding the costly pre-treatment needed for polymeric reverse osmosis membranes. The MFI-type zeolite membrane was developed on a tubular alpha -alumina substrate by a combined rubbing and secondary hydrothermal growth method. The prepared membrane was characterised by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and single gas (He or N sub(2)) permeation, and underwent desalination tests with saline wastewater under different conditions. When saline wastewater was fed at 7 MPa to the zeolite membrane it showed a salt rejection of 80% based on electrical conductivity (EC) and a flux of 4 L m super(-2) h super(-1). A sub(254) (organics absorption at the wavelength of 254 nm measured by a HACH DR5000 spectrophotometer) removal exceeded 90%. Slightly lower salt removal and A sub(254) results were observed when operating at a lower pressure of 3 MPa. During batch concentration runs on the saline wastewater, the EC of the feed water increased from the initial value of 1770 mu S cm super(-1) to 3100 mu S cm super(-1) over the 48 h test time which indicates that a 43% water recovery was achieved. EC reduction remained >70% and flux was maintained at around 2 L m super(-2) h super(-1) throughout the test period, indicating that the membrane resisted organic fouling. Chlorine stability studies showed that a long-term (7 days) strong hypochlorite clean did not significantly alter the flux or rejection confirming the chemical stability of zeolite membranes. Overall, the zeolite membrane showed excellent chemical resilience and produced a desalinated product suitable for reuse applications (e.g. irrigation, residential or industrial). Fluxes, however, need to be improved to be competitive with current polymeric membranes as do rejections for higher purity water applications.
Hygroscopic and acidic nature of organic hole transport layers (HTLs) insisted to replace it with metal oxide semiconductors due to their favorable charge carrier transport with long chemical ...stability. Apart from large direct bandgap and high optical transmittance, ionization energy in the range of −5.0 to −5.4 eV leads to use NiO as HTL due to good energetic matching with lead halide perovskites. Analyzing X‐ray photoelectron spectroscopic (XPS) data of NiO, it is speculated that p‐type conductivity is related to the NiOOH or Ni2O3 states in the structure and the electrical conductivity can be modified by altering the concentration of nickel or oxygen vacancies. However, it is difficult to separate the contribution from nonlocal screening, surface effect and the presence of vacancy induced Ni3+ ion due to very strong satellite structure in the Ni 2p XPS spectrum of NiO. Thus, an effective approach to analyze the NiO XPS spectrum is presented and the way to correlate the presence of Ni3+ with the conductivity results which will help to avoid overestimation in finding the oxygen‐rich/deficient conditions in NiO.
The shoulder peak of Ni2p XPS spectrum is important to understand p‐type semiconducting behavior. Both the Ni 2p and O 1s XPS spectra shall be carefully recorded with fixed take‐off angle (and/or depending on take‐off angle) and compare results with transport measurements.
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