Surface heterojunction based on n-type low-dimensional perovskite film for highly efficient perovskite tandem solar cells.

Enhancing the quality of junctions is crucial for optimizing carrier extraction and suppressing recombination in semiconductor devices. In recent years, metal halide perovskite has emerged as the most promising next-generation material for optoelectronic devices. However, the construction of high-quality perovskite junctions, as well as characterization and understanding of their carrier polarity and density, remains a challenge. In this study, using combined electrical and spectroscopic characterization techniques, we investigate the doping characteristics of perovskite films by remote molecules, which is corroborated by our theoretical simulations indicating Schottky defects consisting of double ions as effective charge dopants. Through a post-treatment process involving a combination of biammonium and monoammonium molecules, we create a surface layer of n-type low-dimensional perovskite. This surface layer forms a heterojunction with the underlying 3D perovskite film, resulting in a favorable doping profile that enhances carrier extraction. The fabricated device exhibits an outstanding open-circuit voltage (VOC) up to 1.34 V and achieves a certified efficiency of 19.31% for single-junction wide-bandgap (1.77 eV) perovskite solar cells, together with significantly enhanced operational stability, thanks to the improved separation of carriers. Furthermore, we demonstrate the potential of this wide-bandgap device by achieving a certified efficiency of 27.04% and a VOC of 2.12 V in a perovskite/perovskite tandem solar cell configuration.

Evaluation of ecotourism suitability based on AHP-GIS: Taking Xiaoxiangling area of the Giant Panda National Park and the surrounding communities as an example.

The primary goal of national parks is to protect ecological environment, but also with the functions of scientific research, education, and recreation. Aiming for the realization of universal sharing, we used the analytic hierarchy process (AHP) to construct an ecotourism suitability evaluation system by selecting four factors, including landscape resources, ecological environment carrying capacity, recreation utilization capacity and social condition, taking Xiaoxiangling area of Giant Panda National Park and the surrounding communities as an example. We evaluated the ecotourism suitability based on GIS, and conducted a questionnaire survey of tourists, to propose suggestions on the functional zoning in terms of ecotourism suitability and subjective choice preferences of tourists. The results showed that the ecotourism suitability of the evaluation area could be classified into five levels. The most suitable areas were located nearby the natural landscape resources and far away from the core conservation area, and the least suitable areas distributed at the edge of the core conservation area. According to the results of suitability analysis, the evaluation area was divided into suitable development area, moderate development area, and restricted development area. Combined with the tourist preferences, we divided the recreational activities in the evaluation area into seven activities, namely, ecotourism, eco-camping, science education, leisure vacation, agricultural and animal husbandry culture experience, eco-education, and mountain adventure. These findings could help provide suitable services for different tourists and offer reference for the ecotourism developmental planning of the Xiaoxiangling area of the Giant Panda National Park.

Association between Soil Physicochemical Properties and Bacterial Community Structure in Diverse Forest Ecosystems.

Although the importance of the soil bacterial community for ecosystem functions has long been recognized, there is still a limited understanding of the associations between its community composition, structure, co-occurrence patterns, and soil physicochemical properties. The objectives of the present study were to explore the association between soil physicochemical properties and the composition, diversity, co-occurrence network topological features, and assembly mechanisms of the soil bacterial community. Four typical forest types from Liziping Nature Reserve, representing evergreen coniferous forest, deciduous coniferous forest, mixed conifer-broadleaf forest, and its secondary forest, were selected for this study. The soil bacterial community was analyzed using Illumina MiSeq sequencing of 16S rRNA genes. Nonmetric multidimensional scaling was used to illustrate the clustering of different samples based on Bray-Curtis distances. The associations between soil physicochemical properties and bacterial community structure were analyzed using the Mantel test. The interactions among bacterial taxa were visualized with a co-occurrence network, and the community assembly processes were quantified using the Beta Nearest Taxon Index (Beta-NTI). The dominant bacterial phyla across all forest soils were Proteobacteria (45.17%), Acidobacteria (21.73%), Actinobacteria (8.75%), and Chloroflexi (5.06%). Chao1 estimator of richness, observed ASVs, faith-phylogenetic diversity (faith-PD) index, and community composition were distinguishing features of the examined four forest types. The first two principal components of redundancy analysis explained 41.33% of the variation in the soil bacterial community, with total soil organic carbon, soil moisture, pH, total nitrogen, carbon/nitrogen (C/N), carbon/phosphorous (C/P), and nitrogen/phosphorous (N/P) being the main soil physicochemical properties shaping soil bacterial communities. The co-occurrence network structure in the mixed forest was more complex compared to that in pure forests. The Beta-NTI indicated that the bacterial community assembly of the four examined forest types was collaboratively influenced by deterministic and stochastic ecological processes.

Population pharmacokinetic/pharmacodynamic modeling of H018, a selective JAK1 inhibitor, in healthy Chinese volunteers.

H018 is an orally administered, selective, small-molecule inhibitor of Janus kinase 1 (JAK1) made for the treatment of rheumatoid arthritis. A population pharmacokinetic/pharmacodynamic analysis was conducted to characterize the pharmacokinetic and pharmacodynamic profile of H018 and its active metabolite using data from 48 healthy Chinese volunteers who received a single dose of 10-160 mg of H018 in a phase I clinical study. A two-compartment model with delayed absorption and linear elimination adequately described the pharmacokinetic data of H018. The apparent clearance of H018 was estimated to be 39.0 L/h, and triglyceride was identified as a covariate on it. Pharmacokinetic data of the active metabolite could be well described by a two-compartment model with linear elimination. The exposure-effect relationships in terms of pSTAT1 inhibition were well described by a direct response model, with exposure captured by an active moiety that consisted of H018 and its metabolite, weighted by the ratio of in vitro JAK1 inhibitory activity (1.13). The estimated EC50 value for the active moiety is 601 nM. In the simulation using the final model, the inhibitory effect appeared to have reached a plateau in the high-dose groups, with max inhibition rates of 81.42 %, 88.42 %, and 91.89 % for 80, 120, and 160 mg dose groups, respectively. Taken together, this study will provide an instructive reference of dose selection for subsequent clinical trials.

Exploring contextual factors impacting the implementation of and engagement with a digital platform supporting psychosis recovery: A brief report.

Individuals with schizophrenia often demonstrate poor engagement in treatment and challenges with illness self-management. App4independence (A4i) is a digital health platform that was developed with the purpose of addressing the aforementioned challenges. While digital interventions can support patient care, there is a paucity of research on implementing such interventions in clinical settings. To describe the contextual factors that impacted the implementation of and engagement with A4i across three different clinical implementation sites, a descriptive approach, guided by implementation science frameworks, was employed to understand how people, culture, process, and technology impacted the implementation of A4i. Descriptive statistics were used to present user engagement data across each site implementation. Additionally, the lessons learned from each implementation were described narratively. Overall, 53 patients were onboarded to A4i in Context 1, 8 in Context 2, and 65 within Context 3, with retention rates over 90 days of 100%, 100%, and 96%, respectively. The adoption, engagement, and sustained use of the A4i platform varied across each implementation site and were affected by implementation strategies within the sociotechnical domains of people, culture, process, and technology. Despite differences in implementation processes, engagement with A4i remained consistently high. Customized educational materials, digital navigators, and technical support served as facilitators in the adoption of A4i.

Digital health tools like, App4Indepence (A4i), have the potential to support people with schizophrenia spectrum disorders in self-managing and engaging in their care. Although it is known that digital tools can support mental health care, there is a lack of knowledge on how best to implement these digital tools into clinical care. Given this, the following brief report aims to describe factors that affected the implementation of A4i across three different clinical settings. An implementation science framework was used to compare and contrast the implementation of A4i across the various clinical settings. Specifically, the impact of people, culture, process, and technology on each implementation was described. Overall, it was found that there were differing rates of engagement with the A4i app across each clinical setting. Higher engagement was found when peer support workers or clinicians were involved in the use of A4i with their clients. In each setting, having a clear implementation plan, creating personalized educational materials, and providing timely and appropriate technical support, facilitated the implementation of the A4i digital platform.

Quantum-Tuned Cascade Multijunction Infrared Photodetector.

Emerging applications such as augmented reality, self-driving vehicles, and quantum information technology require optoelectronic devices capable of sensing a low number of photons with high sensitivity (including gain) and high speed and that could operate in the infrared at telecom windows beyond silicon's bandgap. State-of-the-art semiconductors achieve some of these functions through costly and not easily scalable doping and epitaxial growing methods. Colloidal quantum dots (QDs), on the other hand, could be easily tuned and are compatible with consumer electronics manufacturing. However, the development of a QD infrared photodetector with high gain and high response speed remains a challenge. Herein, we present a QD monolithic multijunction cascade photodetector that advances in the speed-sensitivity-gain space through precise control over doping and bandgap. We achieved this by implementing a QD stack in which each layer is tailored via bandgap tuning and electrostatic surface manipulation. The resulting junctions sustain enhanced local electric fields, which, upon illumination, facilitate charge tunneling, recirculation, and gain, but retain low dark currents in the absence of light. Using this platform, we demonstrate an infrared photodetector sensitive up to 1500 nm, with a specific detectivity of ∼3.7 × 1012 Jones, a 3 dB bandwidth of 300 kHz (0.05 cm2 device), and a gain of ∼70× at 1300 nm, leading to an overall gain-bandwidth product over 20 MHz, in comparison with 3 kHz of standard photodiode devices of similar areas.

Advances in Low-Lactose/Lactose-Free Dairy Products and Their Production.

With increasing health awareness worldwide, lactose intolerance has become a major concern of consumers, creating new market opportunities for low-lactose/lactose-free dairy foods. In recent years, through innovating processes and technologies, dairy manufacturers have significantly improved the variety, and functional and sensory qualities of low-lactose and lactose-free dairy products. Based on this, this paper first covers the pathology and epidemiology of lactose intolerance and market trends. Then, we focus on current advantages and disadvantages of different lactose hydrolysis technologies and improvements in these technologies to enhance nutritional value, and functional, sensory, and quality properties of lactose-free dairy products. We found that more and more cutting-edge technologies are being applied to the production of lactose-free dairy products, and that these technologies greatly improve the quality and production efficiency of lactose-free dairy products. Hopefully, our review can provide a theoretical basis for the marketing expansion and consumption guidance for low-lactose/lactose-free dairy products.

The Protective Role and Mechanism of Mild Therapeutic Hypothermia Protection on Brain Cells.

Background: Moderate therapeutic hypothermia is protective against several cellular stressors. However, the mechanisms behind this protection are not entirely known. In the current investigation, we investigated that therapeutic hypothermia at 33°C administered following peroxide-induced oxidative stress might protect human oligodendroglioma cells using an in vitro model. Methods and Results: Tert-butyl peroxide treatment for one hour significantly increased cell apoptosis and suppressed cell viability. In the range of 50-1000 M tert-butyl peroxide, this cell death was dose-dependent. MTT assay and cell apoptosis assay were applied to analyze cell viability/death at 24 hours after peroxide-induced stress. Therapeutic hypothermia at 33°C delivered for two hours after peroxide exposure significantly increased cell viability and suppressed cell death. Even 15 minutes after peroxide washout when delayed hypothermia was used, this protection was still apparent. Three FDA-approved antioxidants (Tempol, EUK134, and Edaravone at 100 M) were added immediately after tert-butyl peroxide, followed by hypothermia treatment. These three antioxidants greatly increased cell viability and cell apoptosis. RT-qPCR was applied to determine the effects of hypothermia treatment on the expression of caspase-3 and -8 as well as tumor necrosis factor-alpha (TNF-α). Therapeutic hypothermia significantly downregulated these three factors. Conclusion: Overall, these findings confirmed that hypothermia and antioxidants quenching reactive oxygen species may lower mitochondrial oxidative stress and/or apoptotic pathways. Further investigation are needed to investigate the role of hypothermia in other cell models.

Evaluating the Mental Health of Physician-Trainees Using an SMS Text Message-Based Assessment Tool: Longitudinal Pilot Study.

BACKGROUND: Physician burnout is a multibillion-dollar issue in the United States. Despite its prevalence, burnout is difficult to accurately measure. Institutions generally rely on periodic surveys that are subject to recall bias. SMS text message-based surveys or assessments have been used in health care and have the advantage of easy accessibility and high response rates. OBJECTIVE: In this pilot project, we evaluated the utility of and participant engagement with a simple, longitudinal, and SMS text message-based mental health assessment system for physician-trainees at the study institution. The goal of the SMS text message-based assessment system was to track stress, burnout, empathy, engagement, and work satisfaction levels faced by users in their normal working conditions. METHODS: Three SMS text message-based questions per week for 5 weeks were sent to each participant. All data received were deidentified. Additionally, each participant had a deidentified personal web page to follow their scores as well as the aggregated scores of all participants over time. A 13-question optional survey was sent at the conclusion of the study to evaluate the usability of the platform. Descriptive statistics were performed. RESULTS: In all, 81 participants were recruited and answered at least six (mean 14; median 14; range 6-16) questions for a total of 1113 responses. Overall, 10 (17%) out of 59 participants responded "Yes" to having experienced a traumatic experience during the study period. Only 3 participants ever answered being "Not at all satisfied" with their job. The highest number of responses indicating that participants were stressed or burnt out came on day 25 in the 34-day study period. There were mixed levels of concern for the privacy of responses. No substantial correlations were noted between responses and having experienced a traumatic experience during the study period. Furthermore, 12 participants responded to the optional feedback survey, and all either agreed or strongly agreed that the SMS text message-based assessment system was easy to use and the number of texts received was reasonable. None of the 12 respondents indicated that using the SMS text message-based assessment system caused stress. CONCLUSIONS: Responses demonstrated that SMS text message-based mental health assessments are potentially useful for recording physician-trainee mental health levels in real time with minimal burden, but further study of SMS text message-based mental health assessments should address limitations such as improving response rates and clarifying participants' sense of privacy when using the SMS text message-based assessment system. The findings of this pilot study can inform the development of institution-wide tools for assessing physician burnout and protecting physicians from occupational stress.

Comparative Pharmacokinetics and Safety Studies of Dexibuprofen Injection and a Branded Product Ibuprofen Injection in Healthy Chinese Volunteers.

Ibuprofen, a nonsteroidal anti-inflammatory drug, is considered a safe and effective analgesic for treating different types of pain and joint disorders. Dexibuprofen, S-(+)-ibuprofen, is the single pharmacologically active enantiomer of ibuprofen. It is more potent than the racemic formulation of ibuprofen in terms of analgesic and anti-inflammatory properties and causes less acute gastric damage. For the first time, in the present single-dose, randomized, open-label, 2-period crossover study, the safety and pharmacokinetic (PK) characteristics of a single-dose dexibuprofen injection (0.2 g) were evaluated in healthy Chinese subjects and compared with the PK characteristics of a 0.2-g ibuprofen injection. Five consecutive men and women were randomly administered a single dose of the 0.2-g ibuprofen or 0.2-g dexibuprofen injection after fasting in every period during the 5-day interval. Then, plasma samples were collected for liquid chromatography-tandem mass spectrometric analysis. WinNonlin software was used for calculating the PK parameters. The geometric mean ratios of the 0.2-g dexibuprofen injection/ibuprofen injection for maximal plasma concentration, area under the plasma concentration-time curve (AUC) from time 0 to the last quantifiable time point, and AUC from time 0 to infinity were 184.6%, 136.9%, and 134.4%, respectively. The dexibuprofen plasma exposure of the 0.15-g dexibuprofen injection was comparable to that of the 0.2-g ibuprofen injection, calculated using AUC from time 0 to infinity.

Prevalence and associated health and lifestyle factors of myopic maculopathy in northern China: the Kailuan eye study.

BACKGROUND: To evaluate the prevalence and associated health and lifestyle factors of myopic maculopathy (MM) in a northern Chinese industrial city. METHODS: The cross-sectional Kailuan Eye Study included subjects who participated in the longitudinal Kailuan Study in 2016. Ophthalmologic and general examinations were performed on all the participants. MM was graded based on fundus photographs using the International Photographic Classification and Grading System. The prevalence of MM was evaluated. Univariate and multiple logistic regression were adopted to evaluated risk factors of MM. RESULTS: The study included 8330 participants with gradable fundus photographs for MM and ocular biometry data. The prevalence of MM was 1.11% (93/8330; 95% confidence interval [CI] 0.89-1.33%). Diffuse chorioretinal atrophy, patchy chorioretinal atrophy, macular atrophy, and plus lesions were observed in 72 (0.9%), 15 (0.2%), 6 (0.007%), and 32 eyes (0.4%), respectively. MM was more common in eyes with longer axial length (OR 4.517; 95%CI 3.273 to 6.235) and in participants with hypertension (OR 3.460; 95%CI 1.152 to 10.391), and older age (OR 1.084; 95%CI 1.036 to 1.134). CONCLUSIONS: The MM was present in 1.11% of the northern Chinese individuals 21 years or older and the associate factors include longer axial length, older age, and hypertension.

Inhibition of Microglial Activation by Delayed Mild Hypothermia Reduced Preoligodendrocyte Injury in a Neonatal Rat Brain Slice Model.

Periventricular leukomalacia (PVL), characterized by distinctive form of white matter injury, often arises after neonatal cardiac surgery. Proven therapies for PVL are absent. In this study, we designed to quest therapeutic effects of delayed mild hypothermia on PVL and its mechanism in a neonatal rat brain slice model. With the increase of delayed mild hypothermia-treating time, the reduced expression of myelin basic protein and loss of preoligodendrocytes were significantly attenuated after oxygen-glucose deprivation. In addition, the proportion of ionized calcium binding adapter molecule 1 (Iba-1)-positive cells and the expression of Iba-1 were apparently reduced with the increased duration of mild hypothermia treatment. Furthermore, the levels of tumor necrosis factor alpha and interleukin-6 reduced after the mild hypothermia treatment relative to the control. Inhibition of microglial activation with prolonged mild hypothermia may be a potential strategy for white matter protection during cardiopulmonary bypass and hypothermic circulatory arrest.

Comparing the pharmacokinetics, safety, and immunogenicity of HLX02 to US- and EU-approved trastuzumab in healthy Chinese male subjects: A Phase I, randomized, double-blind, parallel-group study.

BACKGROUND: HLX02, the first China-manufactured trastuzumab biosimilar, is approved in Europe (EU) and China. This study evaluated bioequivalence between HLX02 and US-approved trastuzumab (US-trastuzumab). METHOD: In this double-blind, parallel-group, Phase I study, healthy Chinese men were randomized (1:1:1) to receive a single 6 mg/kg dose of HLX02, reference US-trastuzumab, or reference EU-approved trastuzumab (EU-trastuzumab). Equivalence in PK profiles was demonstrated if the 90% confidence intervals (CIs) for the geometric mean ratio (GMR) for the difference between the least square means of the area under the curve (AUC) from time 0 to infinity (AUC∞) were 0.8-1.25. RESULTS: Pharmacokinetic profiles of the three trastuzumab products were similar in 111 Chinese men. Equivalence was confirmed between HLX02 and US-trastuzumab (GMR for AUC∞ 1.009, 90% CI 0.950-1.072); HLX02 and EU-trastuzumab (GMR for AUC∞ 1.068, 90% CI 1.005-1.135); and EU- and US-trastuzumab (GMR for AUC∞ 0.945, 90% CI 0.889-1004). Exploratory analysis of all other PK parameters also demonstrated equivalence between any two of the three trastuzumab products. HLX02 had similar safety and immunogenicity profiles to US- and EU-trastuzumab. CONCLUSION: HLX02 is bioequivalent to US-trastuzumab and EU-trastuzumab, with similar safety and immunogenicity profiles. US- and EU-trastuzumab were also bioequivalent to each other.

Symmetry-Broken 2D Lead-Tin Mixed Chiral Perovskite for High Asymmetry Factor Circularly Polarized Light Detection.

Symmetry-broken-induced spin splitting plays a key role for selective circularly polarized light absorption and spin carrier transport. Asymmetrical chiral perovskite is rising as the most promising material for direct semiconductor-based circularly polarized light detection. However, the increase of asymmetry factor and extension of response region remain to be a challenge. Herein, we fabricated a two-dimensional tin-lead mixed chiral perovskite with tunable absorption in the visible region. Theoretical simulation indicates that the mixing of the tin and lead in chiral perovskite breaks the symmetry of the pure ones, resulting in pure spin splitting. We then fabricated a chiral circularly polarized light detector based on this tin-lead mixed perovskite. A high asymmetry factor for the photocurrent of 0.44 is achieved, which is 144% higher than pure lead 2D perovskite, and it is the highest value reported for the pure chiral 2D perovskite-based circularly polarized light detector using a simple device structure.

Surface-Energy-Regulated Growth of α-Phase Cs0.03 FA0.97 PbI3 for Highly Efficient and Stable Inverted Perovskite Solar Cells.

Methylammonium (MA)-free formamidinium (FA)-dominated Csx FA1-x PbI3 is rising as the most promising candidate for highly efficient and stable perovskite solar cells. However, the growth of high-quality Csx FA1-x PbI3 black-phase perovskite structure without ion doping in the lattice remains a challenge. Herein, propeller-shaped halogenated tertiary ammonium is synthesized, showing high binding energy on the perovskite surface and large steric hindrance. This molecule can significantly reduce the barrier of high surface energy that suppresses the growth of the α-phase Csx FA1-x PbI3 structure. As a result, the α-phase structure can be formed at room temperature, which can further act as a seed for the growth of high-quality film. Solar cells based on the film show a record efficiency up to 23.6% for MA free Csx FA1- x PbI3 solar cells with inverted structure and excellent stability at 85 °C over 200 h.

Connecting Recreational Service to Visitor's Well-Being: A Case Study in Qianjiangyuan National Park.

Natural ecosystems provide service value to people in the region; especially in some nature reserves and national parks, the ecosystem recreational service function is more significant. It is worth paying attention to whether the recreational service function of this ecosystem can serve tourists outside the region and improve their well-being. Taking Qianjiangyuan National Park in China as the research site, based on the Spatially Explicit Ecosystem Services Comprehensive Assessment Model (ESTIMAP), we used the ecosystem services mapping tool to propose a comprehensive assessment framework for ecosystem recreational services and to explore the relationship between recreational services and the well-being of tourists. As a result, we identified the spatial distribution of the supply and demand flow paths of ecosystem recreational services and estimated that the actual flow of ecosystem recreational services was about 12.1 persons/km2 per year. In terms of personal well-being, ecosystem recreational services have a significant positive impact on tourists' well-being. The service value is concentrated in amusement places and recreational activities, and dynamic recreational activities have a greater impact on tourists. The research results suggest that to improve the well-being of tourists and the value of ecosystem recreational services, national parks and nature reserves should improve accessibility and the participation of tourists in recreational activities.

Pharmacokinetics, Bioequivalence, and Safety Studies of a Generic Selective Tyrosine Kinase Inhibitor Nilotinib Capsule Versus a Branded Product in Healthy Chinese Volunteers.

Nilotinib, a second-generation tyrosine kinase inhibitor (TKI), has been approved in the United States and Europe as a treatment for patients with newly diagnosed chronic myeloid leukemia (CML)-chronic phase (CP) and patients with CML-CP or chronic myeloid leukemia-accelerated phase (CML-AP) who are resistant or intolerant to imatinib (a first-generation TKI). This study compared the bioequivalence and safety of the test nilotinib capsule and reference nilotinib capsule (Tasigna, Novartis) in healthy Chinese volunteers under fasting conditions for marketing authorization in China. The results of the study are reported for the first time. This was a single-dose, randomized, open-label, two-period, and cross-over study. Thirty healthy volunteers were randomly assigned to receive a single dose of a 200-mg test or reference capsule under fasting conditions in each period with a 10-day washout. Plasma samples were analyzed with liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were calculated with WinNonlin software. The geometric mean ratio and the corresponding 90% confidence intervals of Cmax , AUC0-t , and AUC0-∞ for nilotinib between the two fixed-dose combination formulations were within the bioequivalence acceptance range of 80%-125%, therefore the generic and branded formulations were bioequivalent in healthy Chinese volunteers.

Lessons learned developing and deploying a provincial virtual mental health support during the COVID-19 pandemic.

Significant efforts have been put into implementing virtual forms of healthcare and supports since the beginning of the pandemic. However, limited information has been shared with health leaders about how this has taken place, and what can be learned from this to move forward into the future. The purpose of this article is to describe lessons learned co-designing and developing a virtual health support during the COVID-19 pandemic in the province of Saskatchewan. In this article, we anchor these lessons learned on a specific virtual health service support, "SaskWell," which offers a digital service, and aims to connect residents of the province to digital mental health supports and resources.

Large Photomultiplication by Charge-Self-Trapping for High-Response Quantum Dot Infrared Photodetectors.

PbS colloidal quantum dots (CQDs) are emerging as promising candidates for next-generation, low-cost, and high-performance infrared photodetectors. Recently, photomultiplication has been explored to improve the detectivity of CQD infrared photodetectors by doping charge-trapping material into a matrix. However, this relies on remote doping that could influence carrier transfer giving rise to limited photomultiplication. Herein, a charge-self-trapped ZnO layer is prepared by a surface reaction between acid and ZnO. Photogenerated electrons trapped by oxygen vacancy defects at the ZnO surface generate a strong interfacial electrical field and induce large photomultiplication at extremely low bias. A PbS CQD infrared photodiode based on this structure shows a response (R) of 77.0 A·W-1 and specific detectivity of 1.5 × 1011 Jones at 1550 nm under a -0.3 V bias. This self-trapped ZnO layer can be applied to other photodetectors such as perovskite-based devices.

Quasi-2D Bilayer Surface Passivation for High Efficiency Narrow Bandgap Perovskite Solar Cells.

The combination of comprehensive surface passivation and effective interface carriers transfer plays a critical role in high-performance perovskite solar cells. A 2D structure is an important approach for surface passivation of perovskite film, however, its large band gap could compromise carrier transfer. Herein, we synthesize a new molecule 2-thiopheneethylamine thiocyanate (TEASCN) for the construction of bilayer quasi-2D structure precisely on a tin-lead mixed perovskite surface. This bilayer structure can passivate the perovskite surface and ensure effective carriers transfer simultaneously. As a result, the open-circuit voltage (Voc ) of the device is increased without sacrificing short-circuit current density (Jsc ), giving rise to a high certified efficiency from a credible third-party certification of narrow band gap perovskite solar cells. Furthermore, theoretical simulation indicates that the inclusion of TEASCN makes the bilayer structure thermodynamically more stable, which provides a strategy to tailor the number of layers of quasi-2D perovskite structures.