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1.
Sensors (Basel) ; 24(9)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38732989

RESUMO

Due to the interaction of accumulated charges on the surface of a test mass with the surrounding electric and magnetic fields, the performance of inertial sensors is affected, necessitating charge management for the test mass. Discharge technology based on Ultraviolet LEDs is internationally recognized as the optimal solution for charge management. Precision driving of Ultraviolet LEDs is considered a key technology in charge management. This paper presents the driving control system used for Ultraviolet LEDs, achieving precision pulse-width-modulation-type current output with controllable pulse width and amplitude. The system generates the pulse-width-controllable pulse voltage signal via analog pulse-width modulation, and subsequently regulates the amplitude of the PWM signal through range switching. To convert the voltage into the pulse-width-modulation-type driving current, the improved Howland current source is employed. The test results demonstrate that the driving control system can output controllable current in the range of 0.01 mA to 10 mA, with a minimum step of 0.01 mA. The accuracy of the current reaches 1%, the stability within 1 h is better than 1%, and the load regulation is better than 2%. The driving control system provides an important reference for the integration of charge management system and the precision drive control method for LEDs.

2.
Adv Sci (Weinh) ; 11(23): e2401313, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38569518

RESUMO

In this study, a novel wide-bandgap small molecule guest material, ITOA, designed and synthesized for fabricating efficient ternary organic solar cells (OSCs) ITOA complements the absorbance of the PM6:Y6 binary system, exhibiting strong crystallinity and modest miscibility. ITOA optimizes the morphology by promoting intensive molecular packing, reducing domain size, and establishing a preferred vertical phase distribution. These features contribute to improved and well-balanced charge transport, suppressed carrier recombination, and efficient exciton dissociation. Consequently, a significantly enhanced efficiency of 18.62% for the ternary device is achieved, accompanied by increased short-circuit current density (JSC), fill factor (FF), and open-circuit voltage (VOC). Building on this success, replacing Y6 with BTP-eC9 leads to an outstanding PCE of 19.33% for the ternary OSCs. Notably, the introduction of ITOA expedites the formation of the optimized morphology, resulting in an impressive PCE of 18.04% for the ternary device without any postprocessing. Moreover, the ternary device exhibits enhanced operational stability under maximum power point (MPP) tracking. This comprehensive study demonstrates that a rationally designed guest molecule can optimize morphology, reduce energy loss, and streamline the fabrication process, essential for achieving high efficiency and stability in OSCs, paving the way for practical commercial applications.

3.
Small ; : e2309827, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38084461

RESUMO

Solution-processed photodetectors have emerged as promising candidates for next-generation of visible-near infrared (vis-NIR) photodetectors. This is attributed to their ease of processing, compatibility with flexible substrates, and the ability to tune their detection properties by integrating complementary photoresponsive semiconductors. However, the limited performance continues to hinder their further development, primarily influenced by the difference of charge transport properties between perovskite and organic semiconductors. In this work, a perovskite-organic bipolar photodetectors (PDs) is introduced with multispectral responsivity, achieved by effectively managing charges in perovskite and a ternary organic heterojunction. The ternary heterojunction, incorporating a designed NIR guest acceptor, exhibits a faster charge transfer rate and longer carrier diffusion length than the binary heterojunction. By achieving a more balanced carrier dynamic between the perovskite and organic components, the PD achieves a low dark current of 3.74 nA cm-2 at -0.2 V, a fast response speed of <10 µs, and a detectivity of exceeding 1012 Jones. Furthermore, a bioinspired retinotopic system for spontaneous chromatic adaptation is achieved without any optical filter. This charge management strategy opens up possibilities for surpassing the limitations of photodetection and enables the realization of high-purity, compact image sensors with exceptional spatial resolution and accurate color reproduction.

4.
Sensors (Basel) ; 23(18)2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37765854

RESUMO

The charge accumulation caused by cosmic rays and solar energetic particles poses a significant challenge as a source of noise for inertial sensors used in space gravitational wave detection. To address this issue, the implementation of charge management systems based on ultraviolet discharge becomes crucial. This paper focuses on elucidating the principles and methods of using ultraviolet discharge for charge management in high-precision inertial sensors. Furthermore, it presents the design and implementation of relevant payloads. Through an analysis of the charge accumulation effect and its impact on noise, key considerations regarding coatings, light sources, and optical paths are explored, and some current and valuable insights into the future development of charge management systems are also summarized. The conclusions drawn from this research also provide guidance for the advancement of higher precision ultraviolet discharge technology and the design of charge management systems.

5.
Sensors (Basel) ; 23(13)2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37447795

RESUMO

Inertial sensors can serve as inertial references for space missions and require charge management systems to maintain their on-orbit performance. To achieve non-contact charge management through UV discharge, effective control strategies are necessary to improve the optical power output performances of UV light sources while accurately modeling their operating characteristics. This paper proposes a low-power photo-electro-thermal model for widely used AlGaN-based UV LEDs, which comprehensively considers the interaction of optical, electrical, and thermal characteristics of UV LEDs during low-power operations. Based on this model, an optical power control system utilizing a fuzzy adaptive PID controller is constructed, in which a switch is introduced to coordinate the working state of the controller. Thus, the steady-state performance is effectively improved while ensuring dynamic performance. The results show that the proposed model has an average prediction error of 5.8 nW during steady-state operations, and the fuzzy adaptive PID controller with a switch can reduce the fluctuation of light output to 0.67 nW during a single discharge task, meeting the charge management requirements of high-precision inertial sensors.


Assuntos
Algoritmos , Lógica Fuzzy , Simulação por Computador , Raios Ultravioleta
6.
Adv Mater ; : e2302915, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37399575

RESUMO

All-small-molecule organic solar cells (ASM-OSCs) have received tremendous attention in recent decades because of their advantages over their polymer counterparts. These advantages include well-defined chemical structures, easy purification, and negligible batch-to-batch variation. Remarkable progress with a power conversion efficiency (PCE) of over 17% has recently been achieved with improved charge management (FF × JSC ) and reduced energy loss (Eloss ). Morphology control is the key factor in the progress of ASM-OSCs, which remains a significant challenge because of the similarities in the molecular structures of the donors and acceptors. In this review, the effective strategies for charge management and/or Eloss reduction from the perspective of effective morphology control are summarized. The aim is to provide practical insights and guidance for material design and device optimization to promote further development of ASM-OSCs to a level where they can compete with or even surpass the efficiency of polymer solar cells.

7.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-995981

RESUMO

As suggested by regulatory feedbacks from relevant national regulatory agencies on the use of medical insurance funds, noticeable problems were found in the compliance and rationality of medical service charges among Chinese hospitals. Based on the practice of hospital management, the authors summarized common problems of various medical service charge management as reported by the management authorities at all levels. These problems referred to name-replaceable charges and affiliated charges, splitting charges, repeated charges, and multiple(false) charges. On this basis, the paper analyzed such hospital management risks incurred as regulatory penalties, fee disputes and medical disputes, as well as their internal and external causes. In the end, the paper put forward countermeasures and suggestions for reference by hospitals in their management of medical service charges.

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