FUDAN University: Chinese Research Output & Key Publications | SinoTechIntel

Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2026

Multi-phase clock generation techniques toward high-frequency and wideband applications

Authors: Junyan Bi, Hao Xu, Na Yan

Multi-phase clocks are fundamental components in modern wireline and wireless communication systems, serving as timing and phase references across diverse architectures. As data rates and carrier frequencies scale, the required phase count and operating frequency have increased substantially, pushing conventional clock generation techniques toward their limits. In high-speed wireline transceivers, multi-phase clocks are essential for CDR phase interpolation, time-interleaved ADCs, and advanced PAM-based modulation, imposing stringent requirements on RMS jitter, phase accuracy, and robustness against PVT variations. In wireless and millimeter-wave systems, they are employed for LO generation, quadrature modulation, and beam steering, where phase accuracy often dominates over absolute jitter. Conventional techniques, including PLL-based dividers, multi-core LC oscillators, and passive phase-shifting networks, face scalability challenges at high frequencies, including limited speed, area overhead, narrowband operation, and sensitivity to mismatch. Ring oscillators offer inherent phase scalability and wide tuning range but suffer from poor stability and jitter. Injection-locked ring oscillators (ILROs) enhance stability and phase noise while preserving multi-phase advantages, yet achieving wide locking range and high phase accuracy simultaneously remains challenging. This research highlight reviews these techniques, discusses their limitations, and outlines advanced injection and feedback schemes to overcome these challenges, aiming to guide future developments in high-frequency and wideband multi-phase clock generation.

Peer ReviewedView Paper→

Nano-Micro Letters•2026

Modulation of Trichromatic Emission Centers in Organic–Inorganic Hybrids for Optoelectronic Applications

Authors: Weidong Cai, Chongyuan Li, Qiang Guo, Fuxiang Ji, Muyi Zhang, Yiqiang Zhan

Organic–inorganic metal halides (OIMHs) have emerged as highly promising novel multifunctional optoelectronic materials, owing to their easily adjustable properties from a variety of combinations of different components. But it is still difficult and rare to realize highly tunable multicolor luminescence within the same material. In this work, we successfully incorporated three adjustable emission centers in OIMHs to synthesize a novel OIMH (NEA)2MnBr4, with each emission center capable of emitting one of the primary colors—red, green, and blue. The green and red emissions originate from the tetrahedron and octahedron structures in the Mn-based frame, while the blue can be attributed to the contribution of organic components. Additionally, to achieve comparable emission intensity among the three primary colors, we enhanced the blue emission performance by optimizing the ratio of organic structure components and incorporating chirality in the OIMHs. The resulting high-quality films can be obtained by spin-coating method with a photoluminescence quantum yields of up to 96%. More interestingly, by the dual manipulation of excitation wavelength and temperature, the sample can be emitted at least seven distinct colors including a standard white luminescence at (0.33, 0.33), opening up promising prospects for multicolor luminescence applications such as high-end anti-counterfeiting technology, light-emitting diodes, X-ray imaging, latent fingerprints, humidity detection, and so on. Therefore, based on application scenarios and requirements, our research on this highly tunable luminescent OIMH material lays a solid foundation for further development of various functional properties of related materials.

Peer ReviewedView Paper→

Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025

PL spectra and PL dynamics of CsPbBr3 quantum dots in solution and film

Authors: Zhengda Dong, Dachuan Li, Pingyuan Yan, Chuanxiang Sheng

Temperature dependent photoluminescence (PL) and time-resolved PL (TRPL) of CsPbBr3 quantum dots (QDs) in solution and film are investigated. The electron−phonon coupling strength of quantum dots in solution is found two times larger than that of thin films. The averaged phonon energy involved in luminescence is also significantly higher than that of thin films, indicating that ligands’ phonons are involved in optical processes in solution but not in film. TRPL shows that the luminescence lifetime of the solution (22.5 ns) is longer than that of the thin film (5 ns) at room temperature, and both decrease abnormally with decreasing temperature, ascribing to the thermally activated trap states for PL, the further analysis shows that the trap energy levels in the thin film are deeper (~20 meV) compared to ~4 meV in solution. Our work proves that the morphology of organic ligands can regulate electron−phonon interactions and optoelectronic properties in CsPbBr3 QDs, providing fundamental insights into its photophysics.

Peer ReviewedView Paper→

Nano-Micro Letters•2025

Enhancement of Li+ Transport Through Intermediate Phase in High-Content Inorganic Composite Quasi-Solid-State Electrolytes

Authors: Haoyang Yuan, Wenjun Lin, Changhao Tian, Mihaela Buga, Tao Huang, Aishui Yu

Quasi-solid-state electrolytes, which integrate the safety characteristics of inorganic materials, the flexibility of polymers, and the high ionic conductivity of liquid electrolytes, represent a transitional solution for high-energy-density lithium batteries. However, the mechanisms by which inorganic fillers enhance multiphase interfacial conduction remain inadequately understood. In this work, we synthesized composite quasi-solid-state electrolytes with high inorganic content to investigate interfacial phenomena and achieve enhanced electrode interface stability. Li1.3Al0.3Ti1.7(PO4)3 particles, through surface anion anchoring, improve Li+ transference numbers and facilitate partial dissociation of solvated Li+ structures, resulting in superior ion transport kinetics that achieve an ionic conductivity of 0.51 mS cm−1 at room temperature. The high mass fraction of inorganic components additionally promotes the formation of more stable interfacial layers, enabling lithium-symmetric cells to operate without short-circuiting for 6000 h at 0.1 mA cm−2. Furthermore, this system demonstrates exceptional stability in 5 V-class lithium metal full cells, maintaining 80.5% capacity retention over 200 cycles at 0.5C. These findings guide the role of inorganic interfaces in composite electrolytes and demonstrate their potential for advancing high-voltage lithium battery technology.

Peer ReviewedView Paper→

Nano-Micro Letters•2025

Probing Interfacial Nanostructures of Electrochemical Energy Storage Systems by In-Situ Transmission Electron Microscopy

Authors: Guisheng Liang, Chang Zhang, Liting Yang, Yihao Liu, Minmin Liu, Xuhui Xiong, Chendi Yang, Xiaowei Lv, Wenbin You, Ke Pei, Chuan-Jian Zhong, Han-Wen Cheng, Renchao Che

The ability to control the electrode interfaces in an electrochemical energy storage system is essential for achieving the desired electrochemical performance. However, achieving this ability requires an in-depth understanding of the detailed interfacial nanostructures of the electrode under electrochemical operating conditions. In-situ transmission electron microscopy (TEM) is one of the most powerful techniques for revealing electrochemical energy storage mechanisms with high spatiotemporal resolution and high sensitivity in complex electrochemical environments. These attributes play a unique role in understanding how ion transport inside electrode nanomaterials and across interfaces under the dynamic conditions within working batteries. This review aims to gain an in-depth insight into the latest developments of in-situ TEM imaging techniques for probing the interfacial nanostructures of electrochemical energy storage systems, including atomic-scale structural imaging, strain field imaging, electron holography, and integrated differential phase contrast imaging. Significant examples will be described to highlight the fundamental understanding of atomic-scale and nanoscale mechanisms from employing state-of-the-art imaging techniques to visualize structural evolution, ionic valence state changes, and strain mapping, ion transport dynamics. The review concludes by providing a perspective discussion of future directions of the development and application of in-situ TEM techniques in the field of electrochemical energy storage systems.

Peer ReviewedView Paper→

Nano-Micro Letters•2025

Understanding the Decoupled Effects of Cations and Anions Doping for High-Performance Perovskite Solar Cells

Authors: Tianxiang Hu, Yixi Wang, Kai Liu, Jia Liu, Haoyang Zhang, Qudrat Ullah Khan, Shijie Dai, Weifan Qian, Ruochen Liu, Yanyan Wang, Chongyuan Li, Zhenru Zhang, Mingxiang Luo, Xiaofei Yue, Chunxiao Cong, Yuan Yongbo, Anran Yu, Jia Zhang, Yiqiang Zhan

The past decade has witnessed the rapid increasement in power conversion efficiency of perovskite solar cells (PSCs). However, serious ion migration hampers their operational stability. Although dopants composed of varied cations and anions are introduced into perovskite to suppress ion migration, the impact of cations or anions is not individually explored, which hinders the evaluation of different cations and further application of doping strategy. Here we report that a special group of sulfonic anions (like CF3SO3−) successfully introduce alkaline earth ions (like Ca2+) into perovskite lattice compared to its halide counterparts. Furthermore, with effective crystallization regulation and defect passivation of sulfonic anions, perovskite with Ca(CF3SO3)2 shows reduced PbI2 residue and metallic Pb0 defects; thereby, corresponding PSCs show an enhanced PCE of 24.95%. Finally by comparing the properties of perovskite with Ca(CF3SO3)2 and FACF3SO3, we found that doped Ca2+ significantly suppressed halide migration with an activation energy of 1.246 eV which accounts for the improved operational stability of Ca(CF3SO3)2-doped PSCs, while no obvious impact of Ca2+ on trap density is observed. Combining the benefits of cations and anions, this study presents an effective method to decouple the effects of cations and anions and fabricate efficient and stable PSCs.

Peer ReviewedView Paper→

Nano-Micro Letters•2025

A Valuable and Low-Budget Process Scheme of Equivalized 1 nm Technology Node Based on 2D Materials

Authors: Yang Shen, Zhejia Zhang, Zhujun Yao, Mengge Jin, Jintian Gao, Yuhan Zhao, Wenzhong Bao, Yabin Sun, He Tian

Emerging two-dimensional (2D) semiconductors are among the most promising materials for ultra-scaled transistors due to their intrinsic atomic-level thickness. As the stacking process advances, the complexity and cost of nanosheet field-effect transistors (NSFETs) and complementary FET (CFET) continue to rise. The 1 nm technology node is going to be based on Si-CFET process according to international roadmap for devices and systems (IRDS) (2022, https://irds.ieee.org/), but not publicly confirmed, indicating that more possibilities still exist. The miniaturization advantage of 2D semiconductors motivates us to explore their potential for reducing process costs while matching the performance of next-generation nodes in terms of area, power consumption and speed. In this study, a comprehensive framework is built. A set of MoS2 NSFETs were designed and fabricated to extract the key parameters and performances. And then for benchmarking, the sizes of 2D-NSFET are scaled to a extent that both of the Si-CFET and 2D-NSFET have the same average device footprint. Under these conditions, the frequency of ultra-scaled 2D-NSFET is found to improve by 36% at a fixed power consumption. This work verifies the feasibility of replacing silicon-based CFETs of 1 nm node with 2D-NSFETs and proposes a 2D technology solution for 1 nm nodes, i.e., "2D eq 1 nm" nodes. At the same time, thanks to the lower characteristic length of 2D semiconductors, the miniaturized 2D-NSFET achieves a 28% frequency increase at a fixed power consumption. Further, developing a standard cell library, these devices obtain a similar trend in 16-bit RISC-V CPUs. This work quantifies and highlights the advantages of 2D semiconductors in advanced nodes, offering new possibilities for the application of 2D semiconductors in high-speed and low-power integrated circuits.

Peer ReviewedView Paper→

Nano-Micro Letters•2025

Thermoelectric Modulation of Neat Ti3C2Tx MXenes by Finely Regulating the Stacking of Nanosheets

Authors: Junhui Tang, Renyang Zhu, Ya-Hsin Pai, Yan Zhao, Chen Xu, Ziqi Liang

Emerging two-dimensional MXenes have been extensively studied in a wide range of fields thanks to their superior electrical and hydrophilic attributes as well as excellent chemical stability and mechanical flexibility. Among them, the ultrahigh electrical conductivity (σ) and tunable band structures of benchmark Ti3C2Tx MXene demonstrate its good potential as thermoelectric (TE) materials. However, both the large variation of σ reported in the literature and the intrinsically low Seebeck coefficient (S) hinder the practical applications. Herein, this study has for the first time systematically investigated the TE properties of neat Ti3C2Tx films, which are finely modulated by exploiting different dispersing solvents, controlling nanosheet sizes and constructing composites. First, deionized water is found to be superior for obtaining closely packed MXene sheets relative to other polar solvents. Second, a simultaneous increase in both S and σ is realized via elevating centrifugal speed on MXene aqueous suspensions to obtain small-sized nanosheets, thus yielding an ultrahigh power factor up to ~156 μW m−1 K−2. Third, S is significantly enhanced yet accompanied by a reduction in σ when constructing MXene-based nanocomposites, the latter of which is originated from the damage to the intimate stackings of MXene nanosheets. Together, a correlation between the TE properties of neat Ti3C2Tx films and the stacking of nanosheets is elucidated, which would stimulate further exploration of MXene TEs.

Peer ReviewedView Paper→