Advancing assessment of responsive feeding environments and practices in child care.

Child care environments offer an ideal setting for feeding interventions. CELEBRATE Feeding is an approach implemented in child care environments in two Maritime Provinces in Canada to support responsive feeding (RF) to foster children's self-efficacy, self-regulation, and healthy relationships with food. This study aimed to describe RF in child care using established and enhanced scoring frameworks. The Environment and Policy Assessment and Observation (EPAO) was modified to reflect RF environments and practices, resulting in our modified EPAO and a CELEBRATE scale. Observations were conducted in 18 child care rooms. Behaviours and environments were scored on both scales, creating 21 RF scores, with a score of '3' indicating the most responsiveness. Descriptive analyses of the scores were conducted. The overall room averages were Mean (M) = 41.00, Standard Deviation (SD) = 7.07 (EPAO), and M = 37.92 SD = 6.50 (CELEBRATE). Most responsive scores among rooms within our EPAO and CELEBRATE scales, respectively, were 'educators not using food to calm or encourage behaviour' (M = 2.94, SD = 0.24; M = 2.98, SD = 0.06) and 'not requiring children to sit at the table until finished' (M = 2.89, SD = 0.47; M = 2.97, SD = 0.12). The least responsive scores within the EPAO were 'educator prompts for children to drink water' (M = 0.78, SD = 0.94) and 'children self-serving' (M = 0.83, SD = 0.38). The least responsive in the CELEBRATE scale were 'enthusiastic role modelling during mealtime' (M = 0.70, SD = 0.68) and 'praise of mealtime behaviour unrelated to food intake' (M = 0.74, SD = 0.55). The CELEBRATE scale captured unique observation information about RF to allow documenting change over time with detailed measurement to inform and support nutrition interventions within child care environments.

A combined computational-biophysical approach to understanding fatty acid binding to FABP7.

Members of the fatty acid binding protein (FABP) family function as intracellular transporters of long-chain fatty acids and other hydrophobic molecules to different cellular compartments. Brain FABP (FABP7) exhibits ligand-directed differences in cellular transport. For example, when FABP7 binds to docosahexaenoic acid (DHA), the complex relocates to the nucleus and influences transcriptional activity, whereas FABP7 bound with monosaturated fatty acids remains in the cytosol. Preferential binding of FABP7 to polyunsaturated fatty acids like DHA has been previously observed and is thought to play a role in differential localization. However, we find that at 37°C, FABP7 does not display strong selectivity, suggesting that the conformational ensemble of FABP7 and its perturbation upon binding may be important. We use molecular dynamics simulations, NMR, and a variety of biophysical techniques to better understand the conformational ensemble of FABP7, how it is perturbed by fatty acid binding, and how this may be related to ligand-directed transport. We find that FABP7 has high degree of conformational heterogeneity that is substantially reduced upon ligand binding. We also observe substantial heterogeneity in ligand binding poses, which is consistent with our finding that ligand binding is resistant to mutations in key polar residues in the binding pocket. Our NMR experiments show that DHA binding leads to chemical shift perturbations in residues near the nuclear localization signal, which may point toward a mechanism of differential transport.

Changes in Household Challenges and Subsequent Child Welfare Report.

INTRODUCTION: Preventing child maltreatment and reducing adverse childhood experiences is critical for improving adult health. To inform prevention efforts, it is necessary to move beyond static risk models and instead model the dynamic changes in household challenges during the prebirth and early childhood periods. This study examined the effect of changes in the number of household challenges from prebirth (12 months before birth of a child) to early childhood (3 years after birth) period on the risk of a child maltreatment report by age 3 years. METHODS: This retrospective cohort study linked data from the Alaska 2009-2011 Pregnancy Risk Assessment Monitoring System, its 3-year follow-up survey, and administrative records through 2019. Participants were 1,699 birthing parents. Latent class analyses identified prebirth and early childhood low- and high-challenge respondent groups on the basis of the level of reported household challenges. The authors then modeled the relationships between group transition membership and the risk of maltreatment using latent transition analysis. Analyses were conducted in 2021. RESULTS: Households transitioning from a high-challenge-prebirth status to a low-challenge-early-childhood status had a lower predicted risk for child services report than households remaining in the high-challenges group. Transitioning from low- to high-challenges status predicted the highest risk for child services report than that of all other groups. CONCLUSIONS: To reduce the risk of child maltreatment and subsequent adverse childhood experiences, healthcare providers should screen parents for the presence of household challenges during both pregnancy and early childhood and connect patients to resources targeted at reducing those challenges and providing continuous familial support.

Understanding FABP7 binding to fatty acid micelles and membranes.

Fatty acid-binding proteins (FABPs) are chaperones that facilitate the transport of long-chain fatty acids within the cell and can provide cargo-dependent localization to specific cellular compartments. Understanding the nature of this transport is important because lipid signaling functions are associated with metabolic pathways impacting disease pathologies including cancer, autism, and schizophrenia. FABPs often associate with cell membranes to acquire and deliver their bound cargo as part of transport. We focus on brain FABP (FABP7), which demonstrates localization to the cytoplasm and nucleus, influencing transcription and fatty acid metabolism. We use a combined biophysical-computational approach to elucidate the interaction between FABP7 and model membranes. Specifically, we use multiple experiments to demonstrate that FABP7 can bind oleic acid and docosahexaenoic acid micelles. Data from NMR and multiscale molecular dynamics simulations reveal that the interaction with micelles is through FABP7's portal region residues. Simulations suggest that binding to membranes occurs through the same residues as micelles. Simulations also capture binding events where fatty acids dissociate from the membrane and enter FABP7's binding pocket. Overall, our data shed light on the interactions between FABP7 and OA or DHA micelles and provide insight into the transport of long-chain fatty acids.

Alaska's Play Every Day Campaign Encourages Parents to Serve Healthy Drinks to Young Children.

BACKGROUND: Sugary drink consumption by young children is a public health concern. The State of Alaska, partnering with the Alaska Native Tribal Health Consortium, implemented the Play Every Day social marketing campaign in 2019-2021 to encourage parents to serve healthy drinks to young children. The campaign's intended audience was parents who experience disproportionately poor nutrition outcomes: Alaska Native people, those living in rural communities, and those with low incomes and/or educational attainment. We described campaign development, implementation, and performance. METHOD: Parents from the identified disproportionately affected populations participated in formative research. Campaign awareness and engagement questions were added to Alaska's child health surveillance system. Regression models assessed associations between campaign exposure and outcomes. RESULTS: The sample included 476 Alaska mothers of 3-year-old children. Of the 34% who reported seeing the campaign, 21% said they changed drinks served to their child because of the campaign. Campaign awareness, engagement, and reported changes in drinks given to children because of the campaign were greater among Alaska Native mothers than White mothers. Among all mothers, those who said the campaign gave them new information or that they shared the campaign had 7 to 8 times greater odds for reporting changes in behavior than those not engaged with the campaign. IMPLICATIONS FOR PRACTICE: Social marketing campaigns that encourage parents to serve healthy drinks to young children may change behavior. Resources should be systematically dedicated to research, implementation, and evaluation focused on specific populations. Partnering with trusted community-serving organizations likely improves outcomes in disproportionately affected populations.

Clinical features and predictive biomarkers for bladder cancer in patients with type 2 diabetes presenting with haematuria.

AIMS: To identify clinical features and protein biomarkers associated with bladder cancer (BC) in individuals with type 2 diabetes mellitus presenting with haematuria. MATERIALS AND METHODS: Data collected from the Haematuria Biomarker (HaBio) study was used in this analysis. A matched sub-cohort of patients with type 2 diabetes and patients without diabetes was created based on age, sex, and BC diagnosis, using approximately a 1:2 fixed ratio. Randox Biochip Array Technology and ELISA were applied for measurement of 66 candidate serum and urine protein biomarkers. Hazard ratios and 95% confidence intervals were estimated by chi-squared and Wilcoxon rank sum test for clinical features and candidate protein biomarkers. Diagnostic protein biomarker models were identified using Lasso-based binominal regression analysis. RESULTS: There was no difference in BC grade, stage, and severity between individuals with type 2 diabetes and matched controls. Incidence of chronic kidney disease (CKD) was significantly higher in patients with type 2 diabetes (p = 0.008), and CKD was significantly associated with BC in patients with type 2 diabetes (p = 0.032). A biomarker model, incorporating two serum (monocyte chemoattractant protein 1 and vascular endothelial growth factor) and three urine (interleukin 6, cytokeratin 18, and cytokeratin 8) proteins, predicted incidence of BC with an Area Under the Curve (AUC) of 0.84 in individuals with type 2 diabetes. In people without diabetes, the AUC was 0.66. CONCLUSIONS: We demonstrate the potential clinical utility of a biomarker panel, which includes proteins related to BC pathogenesis and type 2 diabetes, for monitoring risk of BC in patients with type 2 diabetes. Earlier urology referral of patients with type 2 diabetes will improve outcomes for these patients. TRIAL REGISTRATION: http://www.isrctn.com/ISRCTN25823942.

ABCB10 exports mitochondrial biliverdin, driving metabolic maladaptation in obesity.

Although the role of hydrophilic antioxidants in the development of hepatic insulin resistance and nonalcoholic fatty liver disease has been well studied, the role of lipophilic antioxidants remains poorly characterized. A known lipophilic hydrogen peroxide scavenger is bilirubin, which can be oxidized to biliverdin and then reduced back to bilirubin by cytosolic biliverdin reductase. Oxidation of bilirubin to biliverdin inside mitochondria must be followed by the export of biliverdin to the cytosol, where biliverdin is reduced back to bilirubin. Thus, the putative mitochondrial exporter of biliverdin is expected to be a major determinant of bilirubin regeneration and intracellular hydrogen peroxide scavenging. Here, we identified ABCB10 as a mitochondrial biliverdin exporter. ABCB10 reconstituted into liposomes transported biliverdin, and ABCB10 deletion caused accumulation of biliverdin inside mitochondria. Obesity with insulin resistance up-regulated hepatic ABCB10 expression in mice and elevated cytosolic and mitochondrial bilirubin content in an ABCB10-dependent manner. Revealing a maladaptive role of ABCB10-driven bilirubin synthesis, hepatic ABCB10 deletion protected diet-induced obese mice from steatosis and hyperglycemia, improving insulin-mediated suppression of glucose production and decreasing lipogenic SREBP-1c expression. Protection was concurrent with enhanced mitochondrial function and increased inactivation of PTP1B, a phosphatase disrupting insulin signaling and elevating SREBP-1c expression. Restoration of cellular bilirubin content in ABCB10 KO hepatocytes reversed the improvements in mitochondrial function and PTP1B inactivation, demonstrating that bilirubin was the maladaptive effector linked to ABCB10 function. Thus, we identified a fundamental transport process that amplifies intracellular bilirubin redox actions, which can exacerbate insulin resistance and steatosis in obesity.

Pre-Clinical Common Data Elements for Traumatic Brain Injury Research: Progress and Use Cases.

Traumatic brain injury (TBI) is an extremely complex condition due to heterogeneity in injury mechanism, underlying conditions, and secondary injury. Pre-clinical and clinical researchers face challenges with reproducibility that negatively impact translation and therapeutic development for improved TBI patient outcomes. To address this challenge, TBI Pre-clinical Working Groups expanded upon previous efforts and developed common data elements (CDEs) to describe the most frequently used experimental parameters. The working groups created 913 CDEs to describe study metadata, animal characteristics, animal history, injury models, and behavioral tests. Use cases applied a set of commonly used CDEs to address and evaluate the degree of missing data resulting from combining legacy data from different laboratories for two different outcome measures (Morris water maze [MWM]; RotorRod/Rotarod). Data were cleaned and harmonized to Form Structures containing the relevant CDEs and subjected to missing value analysis. For the MWM dataset (358 animals from five studies, 44 CDEs), 50% of the CDEs contained at least one missing value, while for the Rotarod dataset (97 animals from three studies, 48 CDEs), over 60% of CDEs contained at least one missing value. Overall, 35% of values were missing across the MWM dataset, and 33% of values were missing for the Rotarod dataset, demonstrating both the feasibility and the challenge of combining legacy datasets using CDEs. The CDEs and the associated forms created here are available to the broader pre-clinical research community to promote consistent and comprehensive data acquisition, as well as to facilitate data sharing and formation of data repositories. In addition to addressing the challenge of standardization in TBI pre-clinical studies, this effort is intended to bring attention to the discrepancies in assessment and outcome metrics among pre-clinical laboratories and ultimately accelerate translation to clinical research.

Transition to Adult IBD Care: A Pilot Multi-Site, Telehealth Hybrid Intervention.

OBJECTIVE: Transition to adult IBD care continues to be a challenge. Efficacious models of improving transition to adult care in the United States are lacking. We present data from a pilot, prospective, non-randomized, intervention implemented at IBD centers in the Midwest and Southeast United States. DESIGN AND METHODS: Adolescents and young adults (AYAs; 16-20 years) with IBD and their parents completed a 4- to 5-month transition program (1 in-person group session; 4 individual telehealth sessions). Primary outcomes were feasibility (i.e., recruitment, retention, fidelity) and acceptability (i.e., program satisfaction). Secondary outcomes were changes in transition readiness, self-management skill acquisition, perceived readiness to transfer to adult care, and disease knowledge. RESULTS: The study exceeded goals for recruitment (target N = 20; actual: 36) and retention (target: 80%; actual: 86.11%). On average, it took participants 20.91 ± 3.15 weeks to complete our 4- to 5-month intervention and there were no deviations from the study protocol. Participant ratings for overall program satisfaction, perceived helpfulness, and program length and format were positive. Increases in transition readiness, t(30) = 8.30, d = 1.49, p < .001, self-management skill acquisition, t(30) = 3.93, d = 0.70, p < .001, and disease knowledge, t(30) = 8.20, d = 1.58, p < .001 were noted. AYA- and parent-perceived transfer readiness also improved (p's < .05; d's = 0.76-1.68). CONCLUSIONS: This article presents feasibility and acceptability data for a 4- to 5-month transition intervention. Improvements in AYA transition readiness, self-management skill acquisition, IBD knowledge, and AYA/parent perceived transfer readiness were also observed.

Healing the Hearts of Bereaved Parents: Impact of Legacy Artwork on Grief in Pediatric Oncology.

CONTEXT: Approximately 12% of children with cancer will not survive, representing a devastating loss for parents. Strategies to improve parental coping and grief have been understudied. Although legacy-making is frequently offered as standard care to children with terminal illness and their families, these interventions have received little empirical attention. OBJECTIVES: This study qualitatively explores the legacy-making and grief experiences of bereaved parents who participated in legacy artwork with their child before his or her death from cancer. METHODS: Twelve bereaved parents and 12 healthcare providers participated in individual semistructured interviews guided by the Dual Process Model of Grief and Continuing Bonds theory. Qualitative data were analyzed via conventional content analysis. RESULTS: Five themes emerged. Legacy artwork allows for family bonding and opens communication regarding the child's impending death; provides opportunities for parents to engage in life review and meaning-making; is often displayed in the parents' home after the child's death, and parents take comfort in using these projects to continue their bond with their deceased child; can ameliorate parents' grief after their child's death; and may reduce healthcare providers' compassion fatigue and provide them an outlet for coping with their patients' deaths. CONCLUSION: Participating in legacy artwork may result in self-reported positive outcomes for bereaved parents before and after their child's death, including family bonding, enhanced communication, meaning-making, and improvements in grief. As a result of these benefits, children's hospitals may consider offering legacy artwork for children with cancer and their families.

Modulating cellular cytotoxicity and phototoxicity of fluorescent organic salts through counterion pairing.

Light-activated theranostics offer promising opportunities for disease diagnosis, image-guided surgery, and site-specific personalized therapy. However, current fluorescent dyes are limited by low brightness, high cytotoxicity, poor tissue penetration, and unwanted side effects. To overcome these limitations, we demonstrate a platform for optoelectronic tuning, which allows independent control of the optical properties from the electronic properties of fluorescent organic salts. This is achieved through cation-anion pairing of organic salts that can modulate the frontier molecular orbital without impacting the bandgap. Optoelectronic tuning enables decoupled control over the cytotoxicity and phototoxicity of fluorescent organic salts by selective generation of mitochondrial reactive oxygen species that control cell viability. We show that through counterion pairing, organic salt nanoparticles can be tuned to be either nontoxic for enhanced imaging, or phototoxic for improved photodynamic therapy.

Research and policy priorities for addressing prenatal exposure to opioids in Alaska.

The current opioid crisis in Alaska and the USA will negatively affect the health and wellbeing of future generations. The increasing number of infants born with neonatal opioid withdrawal syndrome (NOWS) has had a profound impact on families, health care providers and the child welfare system. This manuscript summarises the main themes of a Symposium held in Anchorage, Alaska with health care providers, researchers, elders and public health officials that focused on identifying emerging challenges, trends and potential solutions to address the increasing number of infants and children affected by maternal opioid use. Five areas of importance for research and policy development that would direct improvement in the care of infants with NOWS in Alaska are outlined with the goal of supporting a research agenda on opioid misuse and child health across the circumpolar north. Abbreviations: NOWS - neonatal opioid withdrawal syndrome; NAS - neonatal abstinence syndrome; MAT - medication-assisted treatment; NICU - neonatal intensive care unit; OATs - opioid agonist treatments; OCS - office of children's services; ANTHC - Alaska Native Tribal Health Consortium; OUD - opioid use disorder; SBIRT - screening, brief intervention and referral to treatment; ISPCTN - IDeA States Pediatric Clinical Trials Network; NIH - National Institutes of Health; ANMC - Alaska Native Medical Center; DHSS - Department of Health and Social Services; AAPP - All Alaska Pediatric Partnership.

Subjective Versus Objective Measures of Medication Adherence in Adolescents/Young Adults with Attention-Deficit Hyperactivity Disorder.

OBJECTIVE: To examine the frequency of medication nonadherence using both objective and subjective data and to compare the differences between these measures in adolescents and young adults (AYAs) with attention-deficit hyperactivity disorder (ADHD). METHOD: Fifty-four participants enrolled. Frequency (mean percent of prescribed doses not taken) of nonadherence was measured using subjective (visual analog scale) and objective (pill count and electronic monitoring) methods. Differences between measures were compared using t tests and analysis of variances. RESULTS: Objective measures showed that participants missed 40% to 43% of their prescribed doses. Contrastingly, subjective measures indicated that participants missed 25% of their prescribed doses. Frequency of nonadherence was significantly higher when relying on objective measures rather than on subjective measures (t[46] = -4.51, p < 0.01 for pill counts, and t[47] = -4.81, p < 0.01 for electronic monitoring). CONCLUSION: Nonadherence is high in AYAs with ADHD. These individuals tend to overestimate their adherence when self-reporting. Physicians should exercise caution when prescribing based on patient report of adherence and use objective measures when possible.

Enhanced Signal Amplification in a Toll-like Receptor-4 Biosensor Utilizing Ferrocene-Terminated Mixed Monolayers.

A major challenge in effectively treating infections is to provide timely diagnosis of a bacterial or viral agent. Current cell culture methods require >24 h to identify the cause of infection. The Toll-like Receptor (TLR) family of proteins can identify classes of pathogens and has been shown to work well in an impedance-based biosensor, where the protein is attached to an electrode via a self-assembled monolayer (SAM). While the sensitivity of these sensors has been good, they contain a high resistance (>1 kΩ) SAM, generating relatively small signals and requiring longer data collection, which is ill-suited to implementation outside of a laboratory. Here, we describe a novel approach to increase the signal magnitude and decrease the measurement time of a TLR-4 biosensor by inserting a redox-active ferrocenyl-terminated alkanethiol into a mixed SAM containing hydroxyl- and carboxyl-terminated alkanethiols. The SAM formation and modification was confirmed via contact angle and X-ray photoelectron spectroscopy measurements, with TLR-4 immobilization demonstrated through a modified immunosorbent assay. It is shown that these TLR-4 biosensors respond selectively to their intended target, Gram-negative bacteria at levels between 1 and 105 lysed cells/mL, while remaining insensitive to Gram-positive bacteria or viral particles at up to 105 particles/mL. Furthermore, the signal enhancement due to the addition of ferrocene decreased the measurement time to less than 1 min and has enabled this sensor to be used with an inexpensive, portable, hand-held potentiostat that could be easily implemented in field settings.

Impact of Stokes Shift on the Performance of Near-Infrared Harvesting Transparent Luminescent Solar Concentrators.

Visibly transparent luminescent solar concentrators (TLSC) have the potential to turn existing infrastructures into net-zero-energy buildings. However, the reabsorption loss currently limits the device performance and scalability. This loss is typically defined by the Stokes shift between the absorption and emission spectra of luminophores. In this work, the Stokes shifts (SS) of near-infrared selective-harvesting cyanines are altered by substitution of the central methine carbon with dialkylamines. We demonstrate varying SS with values over 80 nm and ideal infrared-visible absorption cutoffs. The corresponding TLSC with such modification shows a power conversion efficiency (PCE) of 0.4% for a >25 cm2 device area with excellent visible transparency >80% and up to 0.6% PCE over smaller areas. However, experiments and simulations show that it is not the Stokes shift that is critical, but the total degree of overlap that depends on the shape of the absorption tails. We show with a series of SS-modulated cyanine dyes that the SS is not necessarily correlated to improvements in performance or scalability. Accordingly, we define a new parameter, the overlap integral, to sensitively correlate reabsorption losses in any LSC. In deriving this parameter, new approaches to improve the scalability and performance are discussed to fully optimize TLSC designs to enhance commercialization efforts.

Parent Perceptions of Their College Students' Self-Management of Attention-Deficit/Hyperactivity Disorder.

PURPOSE: The present study examines parents' perspectives of the experiences and challenges surrounding self-management of Attention-Deficit/Hyperactivity Disorder (ADHD) in their college students. METHODS: Participants were parents of emerging young adults with ADHD prescribed daily medication for their condition. Thirteen individual interviews were conducted using a semistructured interview script guided by the Health Belief Model. The qualitative data were analyzed via directed content analysis. RESULTS: Five themes emerged from the interviews: (1) parents are heavily involved in their child's self-management prior to college, and the abrupt transition of responsibilities is difficult for parents; (2) parents' worries about their child's self-management and functioning are exacerbated by privacy laws and poor communication from child and university; (3) volitional nonadherence is high; (4) obtaining academic accommodations is difficult; and (5) parents recommend a gradual transition, desire enhanced communication from the college, and wish for social support resources in the college setting for their children. CONCLUSIONS: Parents of college students with ADHD are distressed and frustrated by the transition to college. They express the desire to remain continually involved in their child's self-management of ADHD, but several barriers hinder their ability to do so, resulting in fear of the potential consequences on their child's functioning. This collateral information from parents regarding the challenges associated with ADHD self-management experiences in college should result in the development of comprehensive interventions to improve the quality of life in college students with ADHD.

Aqueous-Containing Precursor Solutions for Efficient Perovskite Solar Cells.

Perovskite semiconductors have emerged as competitive candidates for photovoltaic applications due to their exceptional optoelectronic properties. However, the impact of moisture instability on perovskite films is still a key challenge for perovskite devices. While substantial effort is focused on preventing moisture interaction during the fabrication process, it is demonstrated that low moisture sensitivity, enhanced crystallization, and high performance can actually be achieved by exposure to high water content (up to 25 vol%) during fabrication with an aqueous-containing perovskite precursor. The perovskite solar cells fabricated by this aqueous method show good reproducibility of high efficiency with average power conversion efficiency (PCE) of 18.7% and champion PCE of 20.1% under solar simulation. This study shows that water-perovskite interactions do not necessarily negatively impact the perovskite film preparation process even at the highest efficiencies and that exposure to high contents of water can actually enable humidity tolerance during fabrication in air.

Ultrathin Hole Extraction Layer for Efficient Inverted Perovskite Solar Cells.

Inverted perovskite solar cells (PSCs) incorporating poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT) as the hole transport/extraction layer have been broadly investigated in recent years. However, most PSCs which incorporate PEDOT as the hole transport layer (HTL) suffer from lower device performance stemming from reduced photocurrent and low open-circuit voltage around 0.95 V. Here, we report an ultrathin PEDOT layer as the HTL for efficient inverted structure PSCs. The transparency, conductivity, and resulting film morphology were studied and compared with traditional architectures and thicker PEDOT layers. The PSC device incorporating an ultrathin PEDOT layer shows significant improvement in short-circuit current density (J SC), open-circuit voltage (V OC), and power conversion efficiency. Because ultrathin PEDOT layers can be easily obtained by dilution, this study suggests a simple way to improve the PSC performance and provide a route to further reduce the fabrication complexity and cost of PSCs.

Impact of Ultrathin C60 on Perovskite Photovoltaic Devices.

Halide perovskite solar cells have seen dramatic progress in performance over the past several years. Certified efficiencies of inverted structure (p-i-n) devices have now exceeded 20%. In these p-i-n devices, fullerene compounds are the most popular electron-transfer materials. However, the full function of fullerenes in perovskite solar cells is still under investigation, and the mechanism of photocurrent hysteresis suppression by fullerene remains unclear. In previous reports, thick fullerene layers (>20 nm) were necessary to fully cover the perovskite film surface to make good contact with perovskite film and avoid large leakage currents. In addition, the solution-processed fullerene layer has been broadly thought to infiltrate into the perovskite film to passivate traps on grain boundary surfaces, causing suppressed photocurrent hysteresis. In this work, we demonstrate an efficient perovskite photovoltaic device with only 1 nm C60 deposited by vapor deposition as the electron-selective material. Utilizing a combination of fluorescence microscopy and impedance spectroscopy, we show that the ultrathin C60 predominately acts to extract electrons from the perovskite film while concomitantly suppressing the photocurrent hysteresis by reducing space charge accumulation at the interface. This work ultimately helps to clarify the dominant role of fullerenes in perovskite solar cells while simplifying perovskite solar cell design to reduce manufacturing costs.

Anions for Near-Infrared Selective Organic Salt Photovoltaics.

Organic molecular salts are an emerging and highly tunable class of materials for organic and transparent photovoltaics. In this work, we demonstrate novel phenyl borate and carborane-based anions paired with a near-infrared (NIR)-selective heptamethine cation. We further explore the effects of anion structures and functional groups on both device performance and physical properties. Changing the functional groups on the anion significantly alters the open circuit voltage and yields a clear dependence on electron withdrawing groups. Anion exchange is also shown to selectively alter the solubility and film surface energy of the resulting molecular salt, enabling the potential fabrication of solution-deposited cascade or multi-junction devices from orthogonal solvents. This study further expands the catalog and properties of organic salts for inexpensive, and stable NIR-selective molecular salt photovoltaics.