Table of Content

28 November 2025, Volume 1 Issue 3

Previous Issue    Next Issue

Original Article

Mitigating interfacial carrier crowding by an ultrathin LiF interlayer towards efficient and stable perovskite light-emitting diodes

Xiaofei Zhang, Lin Wang, Lingmei Kong, Sheng Wang, Jun Dai, Guohua Jia, Xuyong Yang

2025, 1(3):  199-207.  doi:10.1007/s44275-024-00018-9

Asbtract ( 15 )   PDF (2225KB) ( 0 )  

References | Related Articles | Metrics

Quasi-two-dimensional (quasi-2D) perovskite-based light-emitting diodes (PeLEDs) have attracted intensive attention due to their high quantum yields, tunable emission wavelengths, and solution-processing capability, showing great potential in next-generation display and lighting applications. However, further performance enhancement in PeLEDs is severely limited by the uncontrolled transfer of charge carriers under bias, leading to crowding of interfacial carriers and severe efficiency roll-off. Herein, we insert an ultra-thin dielectric buffer layer of lithium fluoride (LiF) into the electron transport layer (ETL) to regulate the transfer dynamics of electrons and passivate the interfacial defects simultaneously. The dielectric LiF interlayer can effectively reduce the efficiency roll-off in PeLEDs by improving the charge balance through preventing the overwhelming injection of electrons. Moreover, the fluoride anions from LiF can passivate the surface defects of the perovskite film, enhancing the radiative recombination. As a result, the LiF interlayer-assisted quasi-2D PeLED presents an outstanding external quantum efficiency (EQE) of 24.03% and a maximum brightness of 30 845 cd m^-2. The operational stability of the device is also extended, with a half-lifetime (T₅₀) of 71.28 min (at an initial luminance of 1 000 cd m^-2), which is 7.4-fold longer than that for the control device.

Phase change memory programming circuit with improved speed

Xinyu Yang, Yu Lei, Qiuyao Yu, Qian Wang, Houpeng Chen, Zhitang Song

2025, 1(3):  208-218.  doi:10.1007/s44275-024-00023-y

Asbtract ( 16 )   PDF (2295KB) ( 0 )  

References | Related Articles | Metrics

Phase change memory (PCM) is considered one of the most promising next-generation non-volatile memory types for storage-class memory due to its many advantages, including ultrafast programming, long data retention, high storage density, low power consumption, and compatibility with standard CMOS processes. However, in conventional PCM programming circuits, the first programming operation after power-on suffers from a slow rise time in the programming pulse due to the lack of bias voltage pre-charging in the current source circuit, which leads to reduced consistency in the programming of phase change cells. In this study, we developed two solutions to address the issue associated with conventional PCM programming circuits. We also analyzed conventional programming circuit schemes and designed a PCM programming circuit with improved speed using the SMIC 40 nm CMOS process. The results demonstrated that compared with conventional programming circuits, the PCM programming circuit with improved speed reduced the rise time of SET pulses from 29.6 ns to 7.3 ns and the rise time of RESET pulses from 13.6 ns to 3.1 ns. In addition, it improved the consistency of the programming phase change cells and reduced the power consumption from 11.93 mW to 10.35 mW.

Integrated plasmonic ruler using terahertz multi-BIC metasurface for digital biosensing

Qun Ren, Sheng Jia, Jingtong Li, Liu He, Yan Xu, Hao Huang, Xiaoman Wang, ZherYian Ooi, Yongshan Liang, Yaoyin Zhang, Hang Xu, Zhang Zhang, Jianwei You, Wei E. I. Sha, Jianquan Yao

2025, 1(3):  219-231.  doi:10.1007/s44275-025-00027-2

Asbtract ( 20 )   PDF (2424KB) ( 0 )  

References | Related Articles | Metrics

In recent years, continuous bound states in the continuum (BIC) have gained significant attention for their practical applications in optics, chip technology, and modern communication. Traditional approaches to realizing and analyzing BIC typically rely on magnetic dipole models, which have limitations in quantitative analysis and integration. This creates a gap in understanding how to efficiently harness BIC with higher Q-factors for enhanced performance in real-world applications, particularly in scenarios involving terahertz imaging and multi-channel communication. In this study, we introduce a novel approach using a metallic resonator model that leverages toroidal dipole moments to generate symmetry-protected BIC with high Q-factors. By systematically varying the asymmetry parameters of the metasurface, we gradually break its symmetry, achieving a transition from the BIC mode to the quasi-BIC mode and facilitating the gradual release of stored electromagnetic energy. Our theoretical analysis confirms the existence and generation of BIC, and experimental measurements of the transmission response spectrum validate these theoretical predictions. The results indicate that terahertz metasurface with high Q-factors can produce strong resonances at specific frequencies, enhancing resistance to electromagnetic interference and ensuring stable imaging quality in complex environments. Additionally, this study suggests the potential for an integrated plasmonic ruler to achieve high-resolution and efficient biological imaging. These findings bridge the gap by demonstrating how high Q-factor BIC can be effectively utilized for multi-channel terahertz dynamic imaging and biosensing applications. This advancement lays a new foundation for developing robust systems in multi-channel communication and biomedical sensing, offering significant potential for future technological and medical innovations.

Investigating single-molecule fluorescence quenching and molecular motion dynamics at transparent conductive oxide interfaces

Zihan Pan, Jin Lu

2025, 1(3):  232-240.  doi:10.1007/s44275-024-00025-w

Asbtract ( 19 )   PDF (1725KB) ( 0 )  

References | Related Articles | Metrics

The interaction between single-molecule (SM) fluorescence and transparent conductive oxide interface presents unique opportunities for studying molecular motion dynamics and conformational changes. In this study, we investigate the quenching effect of indium-tin oxide (ITO) on SM fluorescence, focusing on the fluorescent dye Cy3 tethered to the 3′-end of single-stranded DNA (ssDNA). By examining the brightness variations of single Cy3 molecules, we are able to distinguish Cy3-ssDNA covalently attached onto the ITO surface from the case of adsorption. Additionally, we can evaluate the molecular motion dynamics of single ssDNA molecules of varying lengths and conformations on the ITO surface. We believe that our findings make significant contributions to the understanding of molecular interactions at ITO interfaces and offer valuable insights into the potential applications of novel fluorophore motion- and orientation-based biosensing strategies.

Review

Smart organic crystalline materials based on photo-induced topochemistry

Yuhui Song, Xiaomin Zhang, Lijian Ning, Qian Zhou, Jinkun Feng, Yanli Wang, Qiuyu Gong, Yinjuan Huang

2025, 1(3):  241-266.  doi:10.1007/s44275-024-00015-y

Asbtract ( 17 )   PDF (4720KB) ( 0 )  

References | Related Articles | Metrics

Presponsive smart organic crystalline materials (SOCMs) have emerged as an attractive research topic because of their many advantages, such as well-defined structures, high structural order, and the resulting fast response speeds, as well as high energy conversion efficiency and remarkable dynamic optical/electronic changes or mechanical responses. In this review, we discuss the recent developments in SOCMs based on topochemistry beyond coordination compounds, which include [2 + 2] or [4 + 4] photocycloaddition of anthracene and olefin derivatives as well as 1, 4-addition-polymerization of diacetylenes. The detailed design principles and mechanisms associated with smart behavior, photoresponsive physical and chemical properties (i.e., photochromism, photo fluorochromism, and photodeformation), and structure-property relationships are discussed, along with their advanced applications in exciting fields such as intelligent microrobots, encryption, sensors, photoactuators, data storage, and displays. Finally, we summarize the current developments and discuss the major current challenges and future opportunities in this field. We expect that this review will inspire more innovative research into the development of advanced photoresponsive organic smart crystal materials with fast, accurate, and reversible responses, and promote the further development of smart materials and devices.

Data encryption based on field effect transistors and memristors

Rumeng Yang, Huiqian Hu, Jianyuan Zhang, Donghui Wang, Weiguo Huang

2025, 1(3):  267-289.  doi:10.1007/s44275-024-00011-2

Asbtract ( 20 )   PDF (8798KB) ( 0 )  

References | Related Articles | Metrics

Information security is a critical requirement across military affairs, business, and daily life. Compared to traditional encryption methods, non-volatile memory offers significant advantages for data encryption due to its high-density storage, reliability, rewrite capability, fast data transport, robust handleability, and ease of integration into electrical circuits. This review comprehensively summarizes the latest advancements in functional materials design and fabrication for data storage and encryption. It highlights innovative techniques that leverage the stimulus including optical, electrical, magnetic, and humidity properties, covering both single-stimulus and multi-stimulus synergistic effect. This review also systematically explores notable progress in the field of encryption. Future research directions will focus on developing ultra-low power devices for data encryption, implementing multiple coordinated encryption techniques, and efficiently integrating advanced devices with algorithms to meet evolving security demands. By offering insights into future trends and challenges, this review aims to deepen understanding and inspire innovative perspectives for the ongoing development of advanced encryption devices.

Stability of p-GaN gate AlGaN/GaN HEMTs under static and dynamic drain stress

Linfei Gao, Xiaohua Li, Wei He, Xinbo Xiong, Huaibao Yan, Hsien-Chin Chiu, Zhanwu Yang, Lixuan Chen, Qiubao Lin, Kaifeng Wang, Hezhou Liu, Xinke Liu

2025, 1(3):  290-299.  doi:10.1007/s44275-025-00029-0

Asbtract ( 18 )   PDF (1746KB) ( 0 )  

References | Related Articles | Metrics

In this article, we report the investigation into the stability of p-GaN gate high electron mobility transistors (HEMTs) with an internal integrated gate circuit that led to the design of a capacitance-based circuit to address threshold voltage shifts (ΔV_TH). Pulse I-V measurement revealed a notable positive gate V_TH shift of 0.7 V as the drain voltage increased from 0 to 650 V, highlighting the impact of drain bias on V_TH instability. Through the investigation of drain bias-induced V_TH instability and the behavior of carriers being transported within the gate region, it was found that the maximum ΔV_TH is 0.4 V when a 200-V drain bias is applied; after stress removal, ΔV_TH diminishes gradually due to the discharge of capacitance, and holes enter the p-GaN layer to mitigate the depletion of holes. The integration of passive components and p-GaN gate HEMT circuits is suggested to address V_TH instability in enhancement-mode HEMT devices. The reliability of power devices is essential for their acceptance in emerging applications.