Electronic Devices Research Articles

Impact of the Lead‐Free Crystal Matrix 0.94NBaTiO3‐0.06SrTiO3 on the Photoluminescence Properties of Eu+3

The investigation reveals that the crystal field environment induces photoluminescence in Eu3+. These synthesized materials hold promise for a wide array of commercial applications, particularly in the light emitting diode industry, representing a significant advancement for the current generation of technology. The lead‐free electroceramics 0.94NB1−xEuxTiO3‐0.06SrTiO3 (x = 0 and x = 0.1) are fabricated using the conventional solid‐state reaction technique. Within these ceramics, both rhombohedral (R3c) and tetragonal (P4mm) structural phases coexist. The structural conformation and fluctuations in average grain size indicate the successful substitution of Eu3+ in 0.94NB1−xTiO3‐0.06SrTiO3 (x = 0). The incorporation of Eu3+ ions into the host matrix induces a long‐range ferroelectric state, marked by a rhombohedral (R3c) distortion, alongside enhanced tetragonal (P4mm) features. This structural modification results from the interaction between the Eu3+ ions and the host lattice, which fosters the emergence of a ferroelectric polarization. The coexistence of rhombohedral and tetragonal symmetries suggests a complex interplay of phases that collectively enhance the material's ferroelectric properties, potentially offering new avenues for applications in electronic and optical devices. Notably, compared to 0.94NB1−xEuxTiO3‐0.06SrTiO3 with (x = 0), the coercive field (Ec) significantly improves, while remanent polarization decreases in the presence of Eu3+. The domain orientation, particularly in Stage‐C, demonstrates a pronounced scaling behavior, which can be attributed to the crystal field surrounding the Eu3+ ions. This interaction influences the material's domain dynamics, enhancing its electromechanical properties. As a result, both of these lead‐free ceramics exhibit considerable potential for future electroceramic applications, offering a promising alternative in environmentally sustainable technologies.

Rapid Prototyping for Accelerated Establishment of Film Processing‐Performance Relationships in Silicon Phthalocyanine OFETs

AbstractUnderstanding the complex relationships underlying the performance of organic electronic devices, such as organic field‐effect transistors (OFETs), requires researchers to navigate a multi‐dimensional parameter space that includes material design, solution formulation, fabrication parameters, and device geometry. Herein, a recently developed materials acceleration platform is demonstrated, named the RoboMapper, to perform direct on‐chip fabrication of OFETs by ultrasonic meniscus printing using silicon phthalocyanine (SiPc) derivatives as the semiconductor. OFETs using bis(tri‐n‐butylsilyl oxide) SiPc ((3BS)2‐SiPc) exhibited the best device performance characterized by the highest electron field‐effect mobility (µe). Through optical microscopy and grazing‐incidence wide‐angle X‐ray scattering (GIWAXS), the favorable performance of (3BS)2‐SiPc is attributed to the specific film morphology and molecular packing achieved with optimal print conditions. Investigating the impact of deposition parameters reveals the crucial role of solvent evaporation rate and print speed in achieving high‐quality film formation. Overall, optimal fabrication conditions for (3BS)2‐SiPc devices include slow print speeds and fast evaporating solutions achieved by using a mixture of co‐solvents and an elevated substrate temperature. The results of this work reveal distinct relationships between deposition conditions, film properties, and device performance for each SiPc derivative and emphasize the necessity of high throughput experimentation to comprehensively understand process‐performance relationships in organic semiconductors.

Complex charge density waves in simple electronic systems of two-dimensional III2–VI3 materials

AbstractCharge density wave (CDW) is the phenomenon of a material that undergoes a spontaneous lattice distortion and modulation of the electron density. Typically, the formation of CDW is attributed to Fermi surface nesting or electron-phonon coupling, where the CDW vector (QCDW) corresponds to localized extreme points of electronic susceptibility or imaginary phonon frequencies. Here, we propose a new family of multiple CDW orders, including chiral Star-of-David configuration in nine 2D III2–VI3 van der Waals materials, backed by first-principles calculations. The distinct feature of this system is the presence of large and flat imaginary frequencies in the optical phonon branch across the Brillouin zone, which facilitates the formation of the diverse CDW phases. The electronic structures of 2D III2–VI3 materials are relatively simple, with only III-s,p and VI-p orbitals contributing to the formation of the CDW order. Despite that, the CDW transitions involve both metal-to-insulator and insulator-to-insulator transitions, accompanied by a significant increase in the bandgap caused by an enhanced electronic localization. Our study not only reveals a new dimension in the family of 2D CDWs, but is also expected to offer deeper insights into the origins of the CDWs.

Presenting a Model for the Evaluation of the Quality of e-learning at Payam Noor University

The current study aims to design a quality evaluation model of the electronic education system at Payam Noor University by applying a mixed methodology. The statistical population of the qualitative section includes twelve professors, researchers, and experts in the field of e-learning, who were selected by selective sampling. The conceptual model of the research was collected after conducting in-depth semi-structured interviews. The quantitative data based on a questionnaire designed by the researcher was collected from 274 professors and students with experience teaching or studying in the electronic education system of Payam Noor University. The data was analyzed using the structural equation modeling method in PLS3 software. The research results show that quality is a concept consisting of four categories behavioral, scientific, cognitive ability, and virtual learning experience. The study’ findings also reveal that cultural, pedagogical, learner, communication, infrastructural, and institutional factors affect the quality of Payam Noor University's electronic education system. Also, the results show that these characteristics will help universities achieve the four outcomes of competitiveness, job opportunities, economy, and reputation by establishing a quality education system. The ideal model for evaluating the quality of e-learning at Payam Noor University is a process approach in which the three dimensions of factors, quality indicators, and outputs are examined and measured. In other words, electronic education is successful when it can create a valuable experience of virtual education while empowering the learners scientifically, behaviorally, and cognitively to let all the stakeholders of higher education benefit from a valuable electronic education.

Investigation of the effect of crystal size on the piezoelectric features of lead-free barium titanate ceramic using molecular dynamics simulation.

This study investigated the piezoelectric properties of BaTiO3 ceramics with different sizes through molecular dynamics simulations. The results show that all samples reached thermal equilibrium at 300K and equilibrium in potential energy within 10ns, confirming effective equilibration. As the size of the ceramics increased, the mean square displacement and diffusion coefficients decreased from 0.217 and 0.0034 to 0.1934 Å2 and 0.003 Å2/ns, attributed to a more uniform microstructure with fewer defects, resulting in reduced ion mobility. Furthermore, saturation polarization, residual polarization, and coercive field values increased from 0.35, 0.1, and 0.175 to 0.42 C/m2, 0.16 C/m2, and 0.282 MV/m, respectively, with increasing sample size, highlighting enhanced polarization responses due to a greater volume of ferroelectric material. Larger barium titanate (BaTiO3) crystals can have better polarization due to more domains aligning, but they may not deform as much (lower strain) because the walls among those domains can't move freely. While improved domain alignment contributed to higher polarization, the increased stress can restrict the mobility of the domain walls. These findings provided valuable insights into the size-dependent behavior of BaTiO3 ceramics, essential for optimizing their applications in electronic devices and sensors. The study underscored the importance of understanding microstructural effects on material properties for future advancements in ferroelectric technology.

Organic Nonvolatile 2T Memory Cell Employing a NOT-Gate-Like Architecture Toward Binary Output Level With Enhanced Noise Tolerance.

Organic nonvolatile memory has been considered a low-cost memory technology for flexible electronics and Internet-of-things (IoT). However, a major concern is the nonuniformity of memory units, which is primarily caused by random grain boundaries, interface defects, and charge traps, making it difficult to develop high-density reliable memory arrays. This nonuniformity problem would induce read error, which is directly caused by the narrow distribution margin of memory states and low noise tolerance in conventional organic memory cells. To break this limitation, a novel 2T memory cell employing a NOT-gate-like architecture achieving self-enhancing noise tolerance is presented. This unique cell consists of a pair of commonly-gated memory transistors with contradictory "write-and-erase" features. It functions as a voltage divider, producing a well-distinguished binary voltage output capability. The concept and design model of this brand-new 2T memory cell is thoroughly discussed. It is originally characterized by noise-tolerant memory cells irrespective of device nonuniformity. The noise tolerance range of this 2T memory cell is also investigated. The binary voltage-readable memory state with a large noise tolerance range is obtained. Moreover, the conceptual design of the 1T2T FeRAM cell is further developed for low-cost voltage-readable memory technology in wearable electronic applications.

High blood pressure in the emergency department as an opportunistic screening tool for detection of hypertension.

Hypertension is the most preventable cause of morbidity and mortality, but many individuals are underdiagnosed and lack treatment control. High blood pressure (BP) in the emergency department (ED) is commonly observed, but mostly used for short-term evaluation. We aimed to study the usefulness of high BP in the ED as a screening tool for undiagnosed hypertension. We used the electronic medical record system to identify all patients that had attended the ED at a university hospital from 2018-01-01 to 2018-03-31 and from 2018-07-01 to 2018-09-30 with an obtained systolic BP ≥ 160 and/or diastolic BP ≥ 100 mmHg measured at the ED. We excluded patients with previously diagnosed hypertension and patients on BP-lowering medication. All patients identified where contacted two years after attending the ED, with a letter of consent and a questionnaire regarding diagnosis of hypertension and current medication. 5424 patients attended the ED during the 6-months-period. 271 patients met the inclusion criteria and were asked to participate. 167 individuals (62%) agreed to participate and responded to the questionnaire. Mean age of participants were 63.1 years and 51% were women. 134 patients (80%) had measured their BP after the ED-visit, and 48 (36%) of those had been diagnosed with hypertension. 96% of patients diagnosed with hypertension were on BP-lowering medication. To follow-up BP ≥ 160/100 mmHg after an ED visit can reveal undiagnosed hypertension in one third of the patients. Given the amount of undiagnosed hypertension, an ED-measured BP might provide an important tool to detect and start treatment of hypertension.

Dielectric properties of chitosan-based ZnO nanocomposites for high-frequency electronic devices

Dielectric properties of chitosan-based ZnO nanocomposites for high-frequency electronic devices

Superior Conductive, Large Diameter CNT Composite Yarn of Insulative Polymer: Inferences of a Unidirectional Compression‐Stretching Technique

ABSTRACTLarge diameter yet highly conductive Carbon Nanotube (CNT) yarn could have prospective control on high‐tech application field spanning from electronic devices to wearable textiles; although the development of such macroscopic CNTs is extremely challenging. Especially, while fabricating CNT composite yarn with polymer, insulative nature of polymeric materials inherently propagates poor electrical conductivity to CNT yarn. To address this, we have proposed an exciting approach to fabricate large dimension, highly conductive yet flexible CNT‐Thermoplastic Polyurethane (TPU) composite yarn through unidirectional compression‐stretching process. Our technique allowed TPU molecules to be well dispersed into inner and inter‐CNT bundles facilitating well flexibility while the simultaneous functions of pressure and tension allowed more closely packed CNTs network within densified CNT yarn reducing the inherent voids and contact resistance. The consequent yarn possessed high conductivity of 1613 S/cm, attractive mechanical performance (tensile strength 1.3 GPa, Young's modulus 12 GPa, toughness 100.75 MJ/m3), exceptional anti‐abrasive ability (up to 46,350 cycles) endowing its multidirectional adaptability for smart textiles. Moreover, the desirable E‐heating performance together with excellent electrical stability allows successful exploitation of the prepared CNT yarn as stretchable heater. Such amazing integrated characteristics may allow the resultant yarn to replace traditional carbon fiber in various high‐tech arena as well.

Enhancing zT in Organic Thermoelectric Materials through Nanoscale Local Control Crystallization.

Organic thermoelectric materials are promising for wearable heating and cooling devices, as well as near-room-temperature energy generation, due to their nontoxicity, abundance, low cost, and flexibility. However, their primary challenge preventing widespread use is their reduced figure of merit (zT) caused by low electrical conductivity. This study presents a method to enhance the thermoelectric performance of solution-processable organic materials through confined crystallization using the lithographically controlled wetting (LCW) technique. Using PEDOT as a benchmark, we demonstrate that controlled crystallization at the nanoscale improves electrical conductivity by optimizing chain packing and grain morphology. Structural characterizations reveal the formation of a highly compact PEDOT arrangement, achieved through a combination of confined crystallization and DMSO post-treatment, leading to a 4-fold increase in the power factor compared to spin-coated films. This approach also reduces the thermal conductivity dependence on electrical conductivity, improving the zT by up to 260%. The LCW technique, compatible with large-area and flexible substrates, offers a simple, green, and low-cost method to boost the performance of organic thermoelectrics, advancing the potential for sustainable energy solutions and advanced organic electronic devices.

Ion-Selective Mobility Differential Amplifier: Enhancing Pressure-Induced Voltage Response in Hydrogels.

Piezoionics is an emerging mechanical-electrical energy conversion paradigm that enables self-powered sensing systems for next-generation intelligent wearable electronics. However, there are currently no rational design approaches to enhance the stimulus response of piezoionic devices. Here, we present a strategy using crown ether as ion-selective mobility differential amplifiers for enhancing the pressured-induced voltage response in ionic polyvinyl alcohol (PVA) hydrogels. The crown ether grafted PVA (PVA-CE) hydrogel prototype achieves a 30-fold amplified piezoionic coefficient of 1490 nV Pa-1 within 0 - 1 kPa, compared to 49 nV Pa-1 of the unmodified PVA. The PVA-CE exhibits an ultra-low pressure detection limit of 0.2 Pa with a fast response time of 18.1 ms. Leveraging these properties, we further demonstrate a human somatosensory network analogous PVA-CE piezoionic skin using arrayed pressure sensing. These capabilities hold great promise for emerging healthcare applications such as synthetic biology, soft robotics, and beyond.

Study of the Mental Health of the Elderly and Related Factors

Background: Aging and increase in the elderly population are the most important issues in recent years in developed countries and some developing countries. Mental health is one of the crucial aspects of elderly well-being and must be addressed to improve community health. This study is conducted to examine the mental health of the elderly and the related factors in Gorgan city, 2022. Methods: The present study is descriptive-analytical and was conducted using a two-stage cluster random sampling method. First, four comprehensive health service centers were selected as a cluster from among the centers of Gorgan city, and then 263 people were randomly selected from the chosen centers, proportionate to the number of registered elderly individuals in the electronic service system. The standard depression questionnaire for the elderly was utilized for assessment. Data were then entered into SPSS software version 18 and with descriptive and analytical statistical tests, including the Mann-Whitney test, Chi-square test, and logistic regression (The significance level was less than 0.05(. Results: A total of 263 elderly people were evaluated with a mean age of 68.64 ± 7.2 . 143 (54.4%) were male and 120 (45.6%) were female. The prevalence of depression was reported to be 27.8. The occurrence of depression was significantly associated with age, marital status, and the presence of underlying disease conditions (p < 0.05). However, gender, place of residence, and BMI did not show a statistically significant relationship with the occurrence of depression. Aging, underlying diseases, and not being married increase the chance of depression in the elderly. Conclusion: Although the prevalence of depression in the elderly is lower than the average of the whole country in this study, they are in a better condition. However, due to the fact that they are a special target group, as well as the various risk factors of the disease, including age, lack of marriage, and the presence of an underlying disease in this group, it is suggested that more appropriate planning be done to improve their mental health status.

A Qualitative Study of School Mental Health Providers’ Experiences with Chart Notes: Perceived Utility, Burden, and Areas for Growth

ABSTRACT Background Despite the ubiquity of chart notes and their well-known impact on medical providers’ job stress and satisfaction, little is known about how mental health providers interact with and are impacted by documentation requirements, particularly in school environments. Objective This qualitative study sought to investigate school mental health providers’ perspectives on and experiences with documentation. Method Four focus groups with eight school mental health providers were conducted. Providers were asked about their current documentation practices and desired changes to their electronic health record system. Recordings of focus groups were transcribed and analyzed for themes using a rapid qualitative analytic approach. Results Key themes revolved around the purpose, features, time demands, training needs, and writing processes surrounding chart notes. Providers reported spending substantial time and energy on documentation and viewed chart notes primarily as a billing requirement, but also valued their utility for treatment planning, outcome monitoring, and clinical accountability. Providers expressed frustration with redundant data entry, lack of protected time for documentation, insufficient training for and communication around updates to documentation requirements, and strained interactions with supervisors during editing. Providers highlighted scheduling protected work time for documentation, enhancing documentation training with a focus on habit formation, standardizing supervisory expectations and providing documentation specific training for supervisors, and redesigning electronic health record interfaces with automation and checklists as strategies that could improve their experiences with chart notes. Conclusions Providers highlighted the ways current training and supervision practices, time constraints, and electronic health record functionality contribute to job stress and burnout while also noting the value of documentation for treatment planning and processing difficult emotions. Roadmaps outlining further research that is needed to understand these suggestions from providers in the larger context of clinical documentation, as well their potential benefits and tradeoffs for providers and other stakeholders, are discussed.

Perioperative direct oral anticoagulant management during cardiac implantable electronic device surgery: an updated systematic review and meta-analysis.

Patients undergoing cardiovascular implantable electronic device (CIED) implantation are often on direct oral anticoagulation (DOAC). However, the evidence on whether to continue or temporarily discontinue DOAC therapy during the perioperative period in these patients is unclear. We conducted a comprehensive literature review using PubMed, Embase, and Cochrane databases through July 2024. We included studies comparing uninterrupted versus interrupted perioperative DOAC therapy in patients undergoing CIED procedure- primary implants, pulse generator replacement, and device upgrades. Primary outcomes were clinically significant device-pocket hematoma and thromboembolic events. Secondary outcomes included any device-pocket hematoma, all-cause mortality, major bleeding, and any bleeding. A total of 1,607 patients from 8 studies were included. The mean age was 73.2years, with atrial fibrillation as the indication for DOAC therapy in most patients. The mean CHA2DS2-VASc was 3.4. Among the included studies, 2 were randomized control trials (RCTs), while the others were observational cohort studies, including one that was propensity score matched. Our meta-analysis found both strategies to be similar in terms of clinically significant pocket hematoma (RR 1.70; 95%CI 0.84-3.45; p = 0.14; I2 = 0%), thromboembolic complications (RR 0.35; 95%CI 0.04-3.32; p = 0.36; I2 = 19%), any pocket hematoma, all-cause mortality and any bleeding with a higher risk of major bleeding with uninterrupted anticoagulation. This meta-analysis shows that uninterrupted DOAC therapy is comparable to interrupted therapy for CIED procedures, with a potential increase in major bleeding risk but low overall complication rates. Further research is needed to confirm the best approach of periprocedural anticoagulation in these patients.

Polycrystalline Diamond Film Growth on Gallium Nitride with Low Boundary Thermal Resistance

As the demand for high-frequency and high-power electronic devices has increased, gallium nitride (GaN), particularly in the context of high-electron mobility transistors (HEMTs), has attracted considerable attention. However, the ‘self-heating effect’ of GaN HEMTs represents a significant limitation regarding both performance and reliability. Diamond, renowned for its exceptional thermal conductivity, represents an optimal material for thermal management in HEMTs. This paper proposes a novel method for directly depositing diamond films onto N-polar GaN (NP-GaN) epitaxial layers. This eliminates the complexities of the traditional diamond growth process and the need for temporary substrate steps. Given the relative lag in the development of N-polar material growth technologies, which are marked by surface roughness issues, and the recognition that the thermal boundary resistance (TBRGaN/diamond) represents a critical factor constraining efficient heat transfer, our study has introduced a series of optimizations to enhance the quality of the diamond nucleation layer while ensuring that the integrity of the GaN buffer layer remains intact. Moreover, chemical mechanical polishing (CMP) technology was employed to effectively reduce the surface roughness of the NP-GaN base, thereby providing a more favorable foundation for diamond growth. The optimization trends observed in the thermal performance test results are encouraging. Integrating diamond films onto highly smooth NP-GaN epitaxial layers demonstrates a reduction in TBRGaN/diamond compared to that of diamond layers deposited onto NP-GaN with higher surface roughness that had undergone no prior process treatment.

Enhancing Regeneration and Functionality of Excitable Tissues via Integrating Bioelectronics and Bioengineered Constructs

Abstract The inherent complexities of excitable cardiac, nervous, and skeletal muscle tissues pose great challenges in constructing artificial counterparts with bioelectrical, structural, and mechanical properties that closely resemble their natural states. Recent advances have increasingly revealed the beneficial impact of bioelectrical microenvironments on cellular behaviors, functional tissue regeneration, and improved therapeutic outcomes for these excitable tissues. This review aims to unveil the mechanisms by which electrical microenvironments enhance the regeneration and functionality of excitable cells and tissues, considering both endogenous electrical cues from electroactive biomaterials and exogenous electrical stimuli from external electronic systems. We explore the synergistic effects of these electrical microenvironments, combined with structural and mechanical guidance, on the regeneration of excitable tissues using tissue engineering scaffolds. Additionally, the emergence of micro/nanoscale bioelectronics has significantly expanded the scope of this field, enabling intimate interactions between implantable bioelectronics and excitable tissues at the cellular, tissue, and organ levels. These interactions allow for precise data extraction and localized modulation of cell and tissue functionalities through intricately designed electronic components according to physiological needs. The integration of tissue engineering and bioelectronics holds the potential to achieve optimal outcomes, highlighting a growing trend in engineering living tissue construct-bioelectronic hybrids for restoring and monitoring damaged excitable tissues. Furthermore, we envision critical challenges in engineering the next generation of these hybrids, focusing on integrated fabrication strategies, the development of ionic conductive biomaterials, and their convergence with biosensors.

Theoretical Design of Smart Bionic Skins with Self-Adaptive Temperature Regulation

Thermal management presents a significant challenge in electric design, particularly in densely packed electronic systems. This study proposes a theoretical model for radiative bionic skin that emulates human skin, enabling the self-adaptive modulation of the thermal exhaustion rate to maintain homeostasis for objects covered by the skin in fluctuating thermal environments. The proposed artificial skin consists of phase change material (VO2) nanoparticles embedded in a low-loss matrix situated on a metallic substrate with a minimal thickness of several micrometers. The findings from our theoretical analyses indicate that substantial alterations in thermal radiation power around the phase transition temperature of 340 K enable a silicone substrate to sustain a relatively stable temperature, with variations confined to ±6 K, despite external heat fluxes ranging from 150 to 450 W/m2. Furthermore, to improve the spectral resemblance to natural skin, a plasmonic surface composed of self-assembled silver nanocubes is incorporated, allowing for modifications to the visible light properties of the bionic skin while maintaining its infrared characteristics. This theoretical investigation offers a cost-effective and conformal approach to the design of ultra-compact, fully passive, and versatile thermal management solutions for robotic systems and related technologies.

Analysis of Legal Protection for Consumers in Trading Through Electronic Systems Based on Minister of Trade Regulation Number 31 of 2023

Trading Through Electronic Systems (PMSE) is a type of trading that is different from conventional trading because it uses an electronic systems. With the rapid advancement of technology, PMSE continues to grow with the emergence of various types of electronic trading. The purpose of this research is to analyze the types of trading through electronic systems and the legal protection provided to consumers engaging in PMSE based on Minister of Trade Regulation Number 31 of 2023. The method used in this research is normative legal research. Normative research involves a literature review with a statutory approach. The results of this study identify various types of PMSE according to Minister of Trade Regulation Number 31 of 2023, as well as several forms of legal protection for consumers participating in PMSE. However, the legal protection offered under this regulation still refers to the Consumer Protection Act. This aspect requires updating, considering the diverse types and forms of PMSE that have emerged.

Does the Traditional Band Picture Correctly Describe the Electronic Structure of n-Doped Conjugated Polymers? A TD-DFT and Natural Transition Orbital Study.

Doped conjugated polymers have a variety of potential applications in thermoelectric and other electronic devices, but the nature of their electronic structure is still not well understood. In this work, we use time-dependent density functional theory (TD-DFT) calculations along with natural transition orbital (NTO) analysis to understand electronic structures of both p-type (e.g., poly(3-hexylthiophene-2,5-diyl), P3HT) and n-type (e.g., poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)}, N2200) conjugated polymers that are both p-doped and n-doped. Of course, the electronic transitions of doped conjugated polymers are multiconfigurational in nature, but it is still useful to have a one-electron energy level diagram with which to interpret their spectroscopy and other electronic behaviors. Based on the NTOs associated with the TD-DFT transitions, we find that the "best" one-electron orbital-based energy level diagram for doped conjugated polymers such as P3HT is the so-called traditional band picture. We also find that the situation is more complicated for donor-acceptor-type polymers like N2200, where the use of different exchange-correlation functionals leads to different predicted optical transitions that have significantly less one-electron character. For some functionals, we still find that the "best" one-electron energy level diagram agrees with the traditional picture, but for others, there is no obvious route to reducing the multiconfigurational transitions to a one-electron energy level diagram. We also see that the presence of both electron-rich and electron-poor subunits on N2200 breaks the symmetry between n- and p-doping, because different types of polarons reside on different subunits leading to different degrees of charge delocalization. This effect is exaggerated by the presence of dopant counterions, which interact differently with n- and p-polarons. Despite these complications, we argue that the traditional band picture suffices if one wishes to employ a simple one-electron picture to explain the spectroscopy of n- and p-doped conjugated polymers.

Azaindole: A Candidate Anchor for Regulating Charge Polarity and Inducing Resonance Transmission at the Fermi Level via Dehydrogenation.

Tuning the polarity of charge carriers is essential for designing molecular logic devices in molecular electronics. In this study, the electrical transport properties of a family of azaindole-anchored single-molecule junctions have been investigated using density functional theory combined with the nonequilibrium Green's function method. The obtained results reveal that dehydrogenation is an effective method for reversing the polarity of charge carriers. The molecular junctions based on the entire azaindole unit are n-type and contain electrons as the principal charge carriers, whereas the dehydrogenated junctions are p-type and contain holes as the main carriers. Furthermore, the azaindole anchors undergo a transition from an electron-rich to an electron-deficient state due to dehydrogenation, which is the original cause of the charge carrier polarity conversion. Dehydrogenated molecular junctions also exhibit the Fermi pinning effect and a sharp highest occupied molecular orbital (HOMO) resonance peak at the Fermi level. In addition, using Pt electrodes instead of Au electrodes is a means of producing a HOMO resonance peak a for azaindole-based molecular junctions. This work demonstrates the enormous potential of utilizing azaindole-anchored molecular junctions for the implementation of molecular logic and multifunctional molecular devices.