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1.
Healthcare (Basel) ; 12(9)2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38727496

RESUMO

Understanding the intricate relationships between diseases is critical for both prevention and recovery. However, there is a lack of suitable methodologies for exploring the precedence relationships within multiple censored time-to-event data, resulting in decreased analytical accuracy. This study introduces the Censored Event Precedence Analysis (CEPA), which is a nonparametric Bayesian approach suitable for understanding the precedence relationships in censored multivariate events. CEPA aims to analyze the precedence relationships between events to predict subsequent occurrences effectively. We applied CEPA to neonatal data from the National Health Insurance Service, identifying the precedence relationships among the seven most commonly diagnosed diseases categorized by the International Classification of Diseases. This analysis revealed a typical diagnostic sequence, starting with respiratory diseases, followed by skin, infectious, digestive, ear, eye, and injury-related diseases. Furthermore, simulation studies were conducted to demonstrate CEPA suitability for censored multivariate datasets compared to traditional models. The performance accuracy reached 76% for uniform distribution and 65% for exponential distribution, showing superior performance in all four tested environments. Therefore, the statistical approach based on CEPA enhances our understanding of disease interrelationships beyond competitive methodologies. By identifying disease precedence with CEPA, we can preempt subsequent disease occurrences and propose a healthcare system based on these relationships.

2.
Sci Data ; 11(1): 371, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605036

RESUMO

The simplified molecular-input line-entry system (SMILES) has been utilized in a variety of artificial intelligence analyses owing to its capability of representing chemical structures using line notation. However, its ease of representation is limited, which has led to the proposal of BigSMILES as an alternative method suitable for the representation of macromolecules. Nevertheless, research on BigSMILES remains limited due to its preprocessing requirements. Thus, this study proposes a conversion workflow of BigSMILES, focusing on its automated generation from SMILES representations of homopolymers. BigSMILES representations for 4,927,181 records are provided, thereby enabling its immediate use for various research and development applications. Our study presents detailed descriptions on a validation process to ensure the accuracy, interchangeability, and robustness of the conversion. Additionally, a systematic overview of utilized codes and functions that emphasizes their relevance in the context of BigSMILES generation are produced. This advancement is anticipated to significantly aid researchers and facilitate further studies in BigSMILES representation, including potential applications in deep learning and further extension to complex structures such as copolymers.

3.
ACS Appl Mater Interfaces ; 16(15): 18800-18811, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38587467

RESUMO

Recently, C60 has emerged as a promising anode material for Li-ion batteries, attracting significant interest due to its excellent lithium storage capacity. The electrochemical performance of C60 as an anode is largely dependent on its internal crystal structure, which is significantly influenced by the synthesis method and corresponding conditions. However, there have been few reports on how the synthesis process affects the crystal structure and Li+ storage capacity of C60. This study used the liquid-liquid interface precipitation method and a low-temperature annealing process to fabricate one-dimensional C60 nanorods (NRs). We thoroughly investigated synthesis conditions, including the growth time, drying temperature, annealing time, and annealing atmosphere. The results demonstrate that these synthesis conditions directly impact the morphology, phase transition, and electrochemical efficiency of pure C60 NRs. Remarkably, the hexagonal close-packed structural C60 NRs-6012h, in a metastable form, exhibits a reversible Li+ storage capacity as an anode material in Li-ion batteries. Furthermore, the face-centered cubic C60 NRs-603001h electrode shows significantly enhanced rate performance and long-cycle stability. A discharge-specific capacity of 603 mAh g-1 was maintained after 2000 cycles at a current density of 2 A g-1. This study elucidates the effect of synthesis conditions on C60 crystals, offering an effective strategy for preparing high-performance C60 anode materials.

4.
Nano Converg ; 10(1): 28, 2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37306870

RESUMO

Perovskite solar cells (PSCs) have the potential to produce solar energy at a low cost, with flexibility, and high power conversion efficiency (PCE). However, there are still challenges to be addressed before mass production of PSCs, such as prevention from degradation under external stresses and the uniform, large-area formation of all layers. Among them, the most challenging aspect of mass production of PSCs is creating a high-quality perovskite layer using environmentally sustainable processes that are compatible with industry standards. In this review, we briefly introduce the recent progresses upon eco-friendly perovskite solutions/antisolvents and film formation processes. The eco-friendly production methods are categorized into two: (1) employing environmentally friendly solvents for perovskite precursor ink/solution, and (2) replacing harmful, volatile antisolvents or even limiting their use during the perovskite film formation process. General considerations and criteria for each category are provided, and detailed examples are presented, specifically focused on the works have done since 2021. In addition, the importance of controlling the crystallization behavior of the perovskite layer is highlighted to develop antisolvent-free perovskite formation methods.

5.
Adv Sci (Weinh) ; 10(20): e2300728, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37144510

RESUMO

The important but remained issue to be addressed to achieve the mass production of perovskite solar modules include a large-area fabrication of high-quality perovskite film with eco-friendly, viable production methods. Although several efforts are made to achieve large-area fabrication of perovskite, the development of eco-friendly solvent system, which is precisely designed to be fit to scale-up methods are still challenging. Herein, this work develops the eco-friendly solvent/co-solvent system to produce a high-quality perovskite layer with a bathing in eco-friendly antisolvent. The new co-solvent/additive, methylsulfonylmethane (MSM), efficiently improves the overall solubility and has a suitable binding strength to the perovskite precursor, resulting in a high-quality perovskite film with antisolvent bathing method in large area. The resultant perovskite solar cells showed high power conversion efficiency of over 24% (in reverse scan), with a good long-term stability under continuous light illumination or damp-heat condition. MSM is also beneficial to produce a perovskite layer at low-temperature or high-humidity. MSM-based solvent system is finally applied to large-area, resulting in highly efficiency perovskite solar modules with PCE of 19.9% (by aperture) or 21.2% (by active area) in reverse scan. These findings contribute to step forward to a mass production of perovskite solar modules with eco-friendly way.

6.
Sci Rep ; 13(1): 435, 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36878960

RESUMO

The significance of simulation has been increasing in device design due to the cost of real test. The accuracy of the simulation increases as the resolution of the simulation increases. However, the high-resolution simulation is not suited for actual device design because the amount of computing exponentially increases as the resolution increases. In this study, we introduce a model that predicts high-resolution outcomes using low-resolution calculated values which successfully achieves high simulation accuracy with low computational cost. The fast residual learning super-resolution (FRSR) convolutional network model is a model that we introduced that can simulate electromagnetic fields of optical. Our model achieved high accuracy when using the super-resolution technique on a 2D slit array under specific circumstances and achieved an approximately 18 times faster execution time than the simulator. To reduce the model training time and enhance performance, the proposed model shows the best accuracy (R2: 0.9941) by restoring high-resolution images using residual learning and a post-upsampling method to reduce computation. It has the shortest training time among the models that use super-resolution (7000 s). This model addresses the issue of temporal limitations of high-resolution simulations of device module characteristics.

7.
J Hazard Mater ; 443(Pt A): 130219, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36367474

RESUMO

The fate and transport of microplastics (MPs) during deep bed filtration were investigated using combined laboratory experiments and numerical modeling. A series of column experiments were conducted within the designated ranges of six operating parameters (i.e., size of the MP and collector, seepage velocity, porosity, temperature, and ionic strength). A variance-based sensitivity analysis, the Fourier amplitude sensitivity test, was conducted to determine the priority in affecting both the attachment coefficient at the pore scale, and the subsequent stabilized height of the breakthrough curve at the continuum scale, which follows non-monotonic trends with singularity in the size of MP (i.e., 1 µm). Finally, Damkohler numbers were introduced to analyze the dominant mechanisms (e.g., attachment, detachment, or straining) in the coupled hydro-chemical process. The robustness of conceptual frameworks bridges the gap between pore-scale interactions and the explicit MPs removal in the continuum scale, which could support decision-making in determining the priority of parameters to retain MPs during deep bed filtration.


Assuntos
Microplásticos , Areia , Plásticos , Filtração , Porosidade
8.
ACS Appl Mater Interfaces ; 14(39): 44303-44316, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36165326

RESUMO

The development of advanced hierarchical anode materials has recently become essential to achieving high-performance sodium-ion batteries. Herein, we developed a facile and cost-effective scheme for synthesizing graphene-wrapped, nitrogen-rich carbon-coated iron sulfide nanofibers (FeS@NCG) as an anode for SIBs. The designed FeS@NCG can provide a significant reversible capacity of 748.5 mAh g-1 at 0.3 A g-1 for 50 cycles and approximately 3.9-fold higher electrochemical performance than its oxide analog (Fe2O3@NCG, 192.7 mAh g-1 at 0.3 A g-1 for 50 cycles). The sulfur- and nitrogen-rich multilayer package structure facilitates efficient suppression of the porous FeS volume expansion during the sodiation process, enabling a long cycle life. The intimate contact between graphene and porous carbon-coated FeS nanofibers offers strong structural barriers associated with charge-transfer pathways during sodium insertion/extraction. It also reduces the dissolution of polysulfides, enabling efficient sodium storage with superior stable kinetics. Furthermore, outstanding capacity retention of 535 mAh g-1 at 5 A g-1 is achieved over 1010 cycles. The FeS@NCG also exhibited a specific capacity of 640 mAh g-1 with a Coulombic efficiency of above 99.8% at 5 A g-1 at 80 °C, indicating its development prospects in high-performance SIB applications.

9.
J Vasc Access ; 23(4): 574-580, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33779359

RESUMO

BACKGROUND: Little is known about the changes in hemodynamic parameters during arteriovenous (AV) access maturation using duplex ultrasound according to radiocephalic fistula (RCF), brachiocephalic fistula (BCF), and AV graft (AVG) in incident hemodialysis (HD) patient. The objective of this study was to evaluate changes and differences in brachial artery flow rate (BAFR) and related parameters affecting maturation by duplex ultrasound in incident HD patients according to access type. METHODS: This study was an observational study conducted from March 2019 to October 2020. During the study period, 109 incident patients underwent new AV access creation, of which 100 were included in the study. The duplex ultrasound was performed on the day prior to access creation, further, day 1, 2 weeks, and 4 weeks later after access creation in incident HD patients. RESULTS: Among all the patients, 38 (38%) received BCF, while 26 (26%) underwent RCF. Of the patients with AVG, 18 (50%) had a forearm loop AVG. The overall mean age was 62.2 ± 13.8 years (range, 32-89). The BAFR increased about 6.9 times in the RCF, 17.4 times in the BCF, and 19.5 times in the AVG at day 1. The median BAFR measured on day 1 was 580.4 mL/min for RC, 1029.0 mL/min for BC, and 1133.0 mL/min for AVG. Relative to the values measured in week 4, the BAFR on day 1 was 69.5% in RCF, 90.6% in BCF, and 93.9% in AVG. The acceleration decreased most significantly on day 1(p < 0.05). The acceleration time increased significantly on day 1 (p < 0.05) and beyond during maturation in the RCF and BCF. The BAFR of the RCF had a significantly negative correlation with the pulsatility index. The BAFR of the BCF showed a significantly positive correlation with the systolic and diastolic blood pressure but negatively correlated with pulse rate. The BAFR of the AVG showed a significant positive correlation with the diameter of the outflow vein. CONCLUSIONS: There were differences in the clinical and duplex parameters during maturation according to access type. The most dramatic changes of duplex parameters were on the day after AV access creation regardless of AV access types. Though RCF had a lower BAFR rate compared to BCF and AVG, it already had a sufficient BAFR required for adequate HD treatment the day after creation. The BAFR of BCF was not different from that of AVG.


Assuntos
Derivação Arteriovenosa Cirúrgica , Idoso , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Artéria Braquial/cirurgia , Antebraço/irrigação sanguínea , Humanos , Pessoa de Meia-Idade , Diálise Renal , Estudos Retrospectivos , Resultado do Tratamento , Ultrassonografia Doppler Dupla , Grau de Desobstrução Vascular
10.
Small Methods ; 5(5): e2001248, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34928076

RESUMO

Perovskite solar cells in an n-i-p structure record high power conversion efficiency, but issues of insufficient thermal stability and the high cost of p-type hole transporting materials have been raised as drawbacks. H2 -phthalocyanine (Pc) is introduced as a hole transport material to ensure the thermal stability and simultaneously have served surface passivation effects on hybrid halide perovskites as a Lewis base. Pyrrolic nitrogen in the Pc reacts with uncoordinated Pb2+ ions on the perovskite surface. Upon enhancing the interfacial interaction between phthalocyanine and the perovskite, the open circuit voltage in devices increases as compared to that of devices using a metal-phthalocyanine complex. While the phthalocyanine-applied device maintains superior thermal long-term stability, the power conversion efficiency also exceeds 20%.

11.
Front Psychol ; 12: 744481, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34707546

RESUMO

A newly developed scale, the Sussex-Oxford Compassion Scale (SOCS) measures compassion for others and the self-based on an empirically supported five-elements definition of compassion: (a) recognizing suffering; (b) understanding the universality of suffering; (c) feeling for the person suffering; (d) tolerating uncomfortable feelings; and (e) motivation to act/acting to alleviate suffering. This study aimed to validate a Korean version of SOCS in a Korean adult sample. We administered the Sussex-Oxford Compassion Scale for Others (SOCS-O), the Sussex-Oxford Compassion Scale for the Self (SOCS-S), and other self-report measures of mindfulness, self-compassion, compassionate love, wellbeing, interpersonal reactivity, and mental health problems to analyze their psychometric properties. The findings support the five-factor hierarchical structure for the SOCS-O and SOCS-S, and as well as both scales' adequate psychometric properties of measurement invariance, interpretability, internal consistency, floor/ceiling effects, and convergent/discriminant validity.

12.
Bioresour Technol ; 341: 125829, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34474239

RESUMO

The stability of dry anaerobic digestion (AD) of food waste (FW) as well as the resulting methane gas generation was investigated from the perspective of system dynamics. Various organic loading rates were applied to the system by modifying the water content in the FW feed and solid retention time (SRT). The excessive organic loading due to the accumulation of volatile fatty acids (VFAs) from the feed with 80% water content during the short SRT (15 and 20 d) caused system failure. In contrast, more intermediate materials, such as VFAs, was easily converted into methane at higher water contents. In addition, the biogas production rate of dry AD was effectively predicted based on SRT, soluble chemical oxygen demand, total VFA, total ammonia, and free ammonia using a recurrent neural network-the so-called "black-box" model. This implies the feasibility of applying this data-based black-box model for controlling and optimizing complex biological processes.


Assuntos
Biocombustíveis , Eliminação de Resíduos , Anaerobiose , Reatores Biológicos , Alimentos , Metano , Redes Neurais de Computação
13.
Kidney Res Clin Pract ; 40(3): 371-382, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34233437

RESUMO

BACKGROUND: Copeptin is secreted in equimolar amounts as arginine vasopressin, main hormone regulating body fluid homeostasis. A recent study reported a copeptin-based classification of osmoregulatory defects in syndromes of inappropriate antidiuresis that may aid in prediction of therapeutic success. We investigated usefulness of copeptin for differentiating etiologies of hyponatremia and predicting efficacy and safety of hypertonic saline treatment in hyponatremic patients. METHODS: We performed a multicenter, prospective cohort study of 100 inpatients with symptomatic hyponatremia (corrected serum sodium [sNa] ≤ 125 mmol/L) treated with hypertonic saline. Copeptin levels were measured at baseline and 24 hours after treatment initiation, and patients were classified as being below or above median of copeptin at baseline or at 24 hours, respectively. Correlations between target, under correction, and overcorrection rates of sNa within 24 hours/24-48 hours and copeptin levels at baseline/24 hours were analyzed. RESULTS: Mean sNa and median copeptin levels were 117.9 and 16.9 pmol/L, respectively. Ratio of copeptin-to-urine sodium allowed for an improved differentiation among some (insufficient effective circulatory volume), but not all hyponatremia etiologic subgroups. Patients with below-median copeptin levels at baseline achieved a higher target correction rate in 6/24 hours (odds ratio [OR], 2.97; p = 0.02/OR, 6.21; p = 0.006). Patients with below-median copeptin levels 24 hours after treatment showed a higher overcorrection rate in next 24 hours (OR, 18.00, p = 0.02). CONCLUSION: There is a limited diagnostic utility of copeptin for differential diagnosis of hyponatremia. However, copeptin might be useful for predicting responses to hypertonic saline treatment in hyponatremic patients.

14.
ACS Appl Mater Interfaces ; 13(26): 30497-30503, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34170671

RESUMO

This report addresses indium oxide doped with titanium and tantulum with high near-infrared transparency to potentially replace the conventional indium tin oxide transparent electrode used in semitransparent perovskite devices and top cells of tandem devices. The high near-infrared transparency of this electrode is possibly explained by the lower carrier concentration, suggesting less defect sites that may sacrifice its optical transparency. Incorporating this transparent electrode into semitransparent perovskite solar cells for both the top and bottom electrodes improved the device performance through possible reduction of interfacial defect sites and modification in energy alignment. With this indium oxide-based semitransparent perovskite top cell, we also demonstrated four-terminal perovskite-silicon tandem configurations with improved photocurrent response in the bottom silicon cell.

15.
Nature ; 590(7847): 587-593, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33627807

RESUMO

Metal halide perovskite solar cells (PSCs) are an emerging photovoltaic technology with the potential to disrupt the mature silicon solar cell market. Great improvements in device performance over the past few years, thanks to the development of fabrication protocols1-3, chemical compositions4,5 and phase stabilization methods6-10, have made PSCs one of the most efficient and low-cost solution-processable photovoltaic technologies. However, the light-harvesting performance of these devices is still limited by excessive charge carrier recombination. Despite much effort, the performance of the best-performing PSCs is capped by relatively low fill factors and high open-circuit voltage deficits (the radiative open-circuit voltage limit minus the high open-circuit voltage)11. Improvements in charge carrier management, which is closely tied to the fill factor and the open-circuit voltage, thus provide a path towards increasing the device performance of PSCs, and reaching their theoretical efficiency limit12. Here we report a holistic approach to improving the performance of PSCs through enhanced charge carrier management. First, we develop an electron transport layer with an ideal film coverage, thickness and composition by tuning the chemical bath deposition of tin dioxide (SnO2). Second, we decouple the passivation strategy between the bulk and the interface, leading to improved properties, while minimizing the bandgap penalty. In forward bias, our devices exhibit an electroluminescence external quantum efficiency of up to 17.2 per cent and an electroluminescence energy conversion efficiency of up to 21.6 per cent. As solar cells, they achieve a certified power conversion efficiency of 25.2 per cent, corresponding to 80.5 per cent of the thermodynamic limit of its bandgap.

16.
Nat Commun ; 11(1): 5146, 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33051454

RESUMO

Driven by recent improvements in efficiency and stability of perovskite solar cells (PSCs), upscaling of PSCs has come to be regarded as the next step. Specifically, a high-throughput, low-cost roll-to-roll (R2R) processes would be a breakthrough to realize the commercialization of PSCs, with uniform formation of precursor wet film and complete conversion to perovskite phase via R2R-compatible processes necessary to accomplish this goal. Herein, we demonstrate the pilot-scale, fully R2R manufacturing of all the layers except for electrodes in PSCs. Tert-butyl alcohol (tBuOH) is introduced as an eco-friendly antisolvent with a wide processing window. Highly crystalline, uniform formamidinium (FA)-based perovskite formation via tBuOH:EA bathing was confirmed by achieving high power conversion efficiencies (PCEs) of 23.5% for glass-based spin-coated PSCs, and 19.1% for gravure-printed flexible PSCs. As an extended work, R2R gravure-printing and tBuOH:EA bathing resulted in the highest PCE reported for R2R-processed PSCs, 16.7% for PSCs with R2R-processed SnO2/FA-perovskite, and 13.8% for fully R2R-produced PSCs.

17.
Death Stud ; 44(5): 261-269, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30623734

RESUMO

The present study aimed to validate a Korean version of the Interpersonal Needs Questionnaire in a college student sample. Three hundred and one students completed the scale and other measures of suicidal ideation, loneliness, interpersonal support, responsibility to family, meaning in life, fearlessness about death, anxiety and depression. Results revealed that the scale has two-factor structure (thwarted belongingness and perceived burdensomeness) and it also has good internal consistency, convergent validity and discriminant validity. Cultural comparisons showed that the levels of thwarted belongingness in Korean college students were higher than those in the U.S. college students.


Assuntos
Relações Familiares , Relações Interpessoais , Psicometria/instrumentação , Psicometria/normas , Apoio Social , Estudantes/psicologia , Adolescente , Adulto , Ansiedade/psicologia , Atitude Frente a Morte , Comparação Transcultural , Depressão/psicologia , Feminino , Humanos , Solidão/psicologia , Masculino , Reprodutibilidade dos Testes , República da Coreia , Estudantes/estatística & dados numéricos , Ideação Suicida , Adulto Jovem
18.
Adv Sci (Weinh) ; 6(14): 1900528, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31380213

RESUMO

Perovskite solar cells (PSCs) with mesoporous TiO2 (mp-TiO2) as the electron transport material attain power conversion efficiencies (PCEs) above 22%; however, their poor long-term stability is a critical issue that must be resolved for commercialization. Herein, it is demonstrated that the long-term operational stability of mp-TiO2 based PSCs with PCE over 20% is achieved by isolating devices from oxygen and humidity. This achievement attributes to systematic understanding of the critical role of oxygen in the degradation of PSCs. PSCs exhibit fast degradation under controlled oxygen atmosphere and illumination, which is accompanied by iodine migration into the hole transport material (HTM). A diffusion barrier at the HTM/perovskite interface or encapsulation on top of the devices improves the stability against oxygen under light soaking. Notably, a mp-TiO2 based PSC with a solid encapsulation retains 20% efficiency after 1000 h of 1 sun (AM1.5G including UV) illumination in ambient air.

19.
Adv Sci (Weinh) ; 6(7): 1802094, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30989030

RESUMO

Recent advances in perovskite solar cells (PSCs) have resulted in greater than 23% efficiency with superior advantages such as flexibility and solution-processability, allowing PSCs to be fabricated by a high-throughput and low-cost roll-to-roll (R2R) process. The development of scalable deposition processes is crucial to realize R2R production of flexible PSCs. Gravure printing is a promising candidate with the benefit of direct printing of the desired layer with arbitrary shape and size by using the R2R process. Here, flexible PSCs are fabricated by gravure printing. Printing inks and processing parameters are optimized to obtain smooth and uniform films. SnO2 nanoparticles are uniformly printed by reducing surface tension. Perovskite layers are successfully formed by optimizing the printing parameters and subsequent antisolvent bathing. 2,2',7,7'-Tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene is also successfully printed. The all-gravure-printed device exhibits 17.2% champion efficiency, with 15.5% maximum power point tracking efficiency for 1000 s. Gravure-printed flexible PSCs based on a two-step deposition of perovskite layer are also demonstrated. Furthermore, a R2R process based on the gravure printing is demonstrated. The champion efficiency of 9.7% is achieved for partly R2R-processed PSCs based on a two-step fabrication of the perovskite layer.

20.
Nature ; 567(7749): 511-515, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30918371

RESUMO

Perovskite solar cells typically comprise electron- and hole-transport materials deposited on each side of a perovskite active layer. So far, only two organic hole-transport materials have led to state-of-the-art performance in these solar cells1: poly(triarylamine) (PTAA)2-5 and 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD)6,7. However, these materials have several drawbacks in terms of commercialization, including high cost8, the need for hygroscopic dopants that trigger degradation of the perovskite layer9 and limitations in their deposition processes10. Poly(3-hexylthiophene) (P3HT) is an alternative hole-transport material with excellent optoelectronic properties11-13, low cost8,14 and ease of fabrication15-18, but so far the efficiencies of perovskite solar cells using P3HT have reached only around 16 per cent19. Here we propose a device architecture for highly efficient perovskite solar cells that use P3HT as a hole-transport material without any dopants. A thin layer of wide-bandgap halide perovskite is formed on top of the narrow-bandgap light-absorbing layer by an in situ reaction of n-hexyl trimethyl ammonium bromide on the perovskite surface. Our device has a certified power conversion efficiency of 22.7 per cent with hysteresis of ±0.51 per cent; exhibits good stability at 85 per cent relative humidity without encapsulation; and upon encapsulation demonstrates long-term operational stability for 1,370 hours under 1-Sun illumination at room temperature, maintaining 95 per cent of the initial efficiency. We extend our platform to large-area modules (24.97 square centimetres)-which are fabricated using a scalable bar-coating method for the deposition of P3HT-and achieve a power conversion efficiency of 16.0 per cent. Realizing the potential of P3HT as a hole-transport material by using a wide-bandgap halide could be a valuable direction for perovskite solar-cell research.

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