CRS_CityU104/23
Integrated Material Design and Device Engineering to Overcome the Limits of Non-radiative Losses and Stability in Next-generation Organic Photovoltaics

Hong Kong Project Coordinator: Prof Kwan-yue Alex Jen (City University of Hong Kong)
Mainland Project Coordinator: Prof Hongzheng Chen (Zhejiang University)

Organic photovoltaic (OPV) is an emerging photovoltaic (PV) technology that employs organic semiconductors that have the same elemental composition as plastic for light-to-electricity conversion. This not only ensures its environmental sustainability over inorganic PVs (silicon, GaAs, perovskite, etc.) mostly comprising heavy metals, but makes OPVs intrinsically flexible and stretchable, distinguishing it from other conventional PV technologies. The diverse form factors and colour tunability allow OPVs to be integrated with flexible/wearable electronics, sensors, semi-transparent PV windows, and versatile low-power applications for indoors.

To facilitate the practical deployment of OPVs, in this proposal, we propose to establish new material design and device engineering strategies that can fundamentally address the major challenges of performance and stability in the field. A major hurdle limiting OPV performance is that the photogenerated charges in organics are prone to non-radiative recombination, thereby converting solar energy only into heat instead of electricity. To mitigate this issue, we plan to design organic photoactive materials with strong luminescent properties to suppress non-radiative transitions. The next issue is the operational stability and lifetime of OPVs, which we aim to address through designing photoactive materials with intrinsically better stability and lower diffusivity under heating and illumination. These efforts will allow us to achieve ≥22% PCEs on research OPV cells with a T80 lifetime ≥2000 hours, offering opportunities for next-generation OPVs to compete with several inorganic PV technologies.

CRS_CUHK403/23
Molecular Mechanisms Underlying Specification and Differentiation of Posterior Cranial Placodes

Hong Kong Project Coordinator: Prof Mai-har Sham (The Chinese University of Hong Kong)
Mainland Project Coordinator: Prof Zhiyong Liu (Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences)

The cranial placodes are multipotent progenitors which give rise to diverse cell types during sensory development of the mammalian head. The posterior placodes consist of two distinct groups of placodal cells: the otic placode which gives rise to the inner ear structures as well as the spiral and vestibular ganglia for hearing and balancing functions; the epibranchial placode which gives rise to the geniculate, petrosal and nodose ganglia that innervate the face, mouth, pharynx, and visceral organs. Abnormal development of the posterior placodes and their derivatives will lead to deafness as well as a range of craniofacial defects.

The development of the posterior placodes is orchestrated by a cascade of transcriptional regulation and signaling pathways, but current studies at cellular and molecular levels remain limited. The Sham group (Hong Kong) and the Liu group (Shanghai, mainland) have been studying posterior placode development and neurogenesis through various cellular and genetic approaches. We have demonstrated the dynamic requirement of Notch signaling factors in directing the differentiation of neural and non-neural derivatives of the epibranchial placode. In our collaborative study, using single-cell transcriptome, and mouse mutant analyses, we have identified a common pool of posterior placodal progenitors. Using cell-type specificity and temporal expression as criteria, we have discovered a number of transcription factors including Tbx1/2 and Tlx3 which are required for placodal progenitor maintenance and ganglia neurogenesis.

In this study, we will address how the common posterior placodal progenitor cell state is induced and maintained; how otic and epibranchial placodes are specified from the common progenitors; how the subdomains of these placodes are determined and differentiated; and how the neuronal fates are determined in the placode derived ganglia. Using single-cell transcriptomics, epigenomics, mouse mutants, and in vitro organoid culture platforms, we will: 1) elucidate the functional hierarchy of the gene regulatory network and signaling factors for the specification of otic and epibranchial placodes; 2) investigate the network of transcriptional regulation for neurogenic differentiation of otic and epibranchial placode derived cranial ganglia. It is expected that through this collaborative study, we will decipher the transcriptional and signaling mechanisms underlying the stepwise specification and neurogenic processes of the posterior placodes. The results obtained from this project will provide novel insight into our understanding of the multipotent placodal progenitors; and facilitate the development of future strategies for the regeneration of sensory and neural cell types.

CRS_CUHK405/23
Cellular and Molecular Mechanisms Underlying Deubiquitinating Enzyme AMSHs in Regulating Autophagosome and MVB Formation in Arabidopsis

Hong Kong Project Coordinator: Prof Liwen Jiang (The Chinese University of Hong Kong)
Mainland Project Coordinator: Prof Shi Xiao (Sun Yat-Sen University)

Autophagy and multivesicular body (MVB)-mediated vacuolar sorting are key biological processes in eukaryotes including plants to maintain cellular homeostasis, which play essential roles in regulating the growth and development of plants. Post-translational modifications of AUTOPHAGY-ASSOCIATED (ATG) and ENDOSOMAL SORTING COMPLEX REQUIRED FOR TRANSPORT (ESCRT) machineries play central roles in the regulation of plant autophagy and vacuolar sorting pathways. Particularly, recent findings from our collaborative research demonstrated that in the model plant Arabidopsis thaliana, a family of six E3 protein ligases SINATs-mediated ubiquitination participates in maintaining protein stabilities of ATG13, ATG6, the plant-unique ESCRT component FREE1, and VPS23a, key regulators of autophagosome formation and MVB biogenesis in plants. Conversely, increasing evidence suggests that the ubiquitination status of protein substrates is also controlled by the activity of deubiquitinases (DUBs), however, the involvement of deubiquitinases in regulating plant autophagy and MVB biogenesis remains elusive. In this project we aim to identify the ATG- and ESCRT-associated deubiquitinases and reveal the molecular mechanisms underlying their participation in the regulation of autophagosome formation and MVB biogenesis in plants. Our studies will provide not only new insights about DUBs-regulated organelle biogenesis and function in plants, but also the theoretical basis for their potential applications in agricultural biotechnology. Our goals will be achieved by joint efforts of three well-complemented areas in plant physiology and molecular biology (Prof. Shi Xiao, Sun Yat-sen University), plant cell biology (Prof. Liwen Jiang, the Chinese University of Hong Kong) and mass spectrometry and protein science (Prof. Zhongping Yao, The Hong Kong Polytechnic University) with international reputations and excellent track record of joint publications derived from our collaborative research.

CRS_PolyU501/23
Efficient Scheduling of Integrated Cloud-Edge-End Computing Power for AI-enabled Applications

Hong Kong Project Coordinator: Prof Jiannong Cao (The Hong Kong Polytechnic University)
Mainland Project Coordinator: Prof Kun Xie (Hunan University)

Cloud computing and edge computing are two key enabling technology for many applications. Cloud is well-suited for resource-greedy computation, while edge outperforms in real-time processing. However, emerging advanced applications such as VR/AR, autonomous vehicles, and industrial IoT require both resource-intensive computation and low-latency processing, as well as large-scale deployment. Existing approaches are inadequate to address the new challenges. Recently, computing power network (CPN) was proposed, which envisions connecting ubiquitous computing power in a network and intelligently scheduling the computation tasks to provide high-performance services.

Most existing works focus on cloud-based CPN, which aim to enable resource and data sharing among cloud data centers but fail to provide applications with real-time response. Few works explore integrating cloud and edge computing power, but they lack efficient computing power scheduling and sufficient support for AI applications.

In this project, we propose a systematic framework for cloud-edge-end-integrated computing power management and scheduling to support resource-greedy and latency-sensitive AI-empowered applications. Our system senses the resource status of the ubiquitous cloud-edge-end computing power and integrates them to construct a federated resource pool. With novel and innovative scheduling mechanisms, various computational workloads including AI model training and inference can be allocated properly within the resource pool to achieve optimal application performance and resource utilization.

We will develop the framework with novel architecture, methodologies, and algorithms to address the challenging issues, including large-scale network and heterogeneous computing power measurement, resource heterogeneity, large-scale task scheduling, and diversity and complexity of AI models. More specifically, 1) Design low-cost networking monitoring and accurate computing power measurement mechanisms to sense the resource status. 2) Design and develop high-performance CPN management architecture and scheduling framework to manage distributed resources. 3) Design resource-aware scheduling algorithms to improve the training performance by jointly considering the coupled computation, networking and data resources, and the requirements of AI tasks. 4) Design performance-guaranteed task scheduling algorithms for optimizing collaborative AI inference tasks. To demonstrate the academic merit and practical impact, we will develop a prototype system with an example application in XR video live streaming.

The novelty and uniqueness of this project lie in the strategical identification of the most critical scientific challenges and a systematic approach to developing innovative solutions, including a new framework, methods, algorithms, and a real-world testbed. This project is timely and has great potential to contribute to the construction of national CPN and benefit a wide range of applications.

CRS_PolyU503/23
Develop Next-generation Typhoon-resistant Deep-sea Offshore Floating Hybrid Wind-wave Energy Converters: From Coupling Load Mechanism to Vibration Mitigation Technology

Hong Kong Project Coordinator: Prof Songye Zhu (The Hong Kong Polytechnic University)
Mainland Project Coordinator: Prof Shitang Ke (Nanjing University of Aeronautics and Astronautics)

Renewable energy has gained worldwide popularity as an alternative energy source with modest environmental impact. Among various renewable energy sources, wind and wave energy are appealing options to achieve the global goal of “carbon neutrality”. The combination of wind and wave energy has become an emerging trend because of their wide availability in sea environments, shared supporting structures, and the corresponding space optimization. Developing next-generation floating hybrid offshore wind-wave energy converters (HOWWECs) has prominent potential in China, considering China’s long coastline. However, these areas are also frequently attacked by typhoons that often cause catastrophic failure of offshore structures.

Compared with traditional offshore wind turbines and wave energy converters, the floating HOWWEC development is still in its early stage. Exposed to harsh sea environments, HOWWECs are constantly subjected to concurrent wind-wave-current loads under operational and extreme conditions. The understanding of HOWWEC’s coupling dynamics remains extremely limited, which presents a major technical obstacle toward a rational design of floating HOWWECs against super typhoons. This proposed project aims to fill these research gaps by collaboratively conducting a combination of analytical, numerical, and experimental investigations on this novel system in this project. The outcome of this project will be an essential step toward the development of next-generation typhoon-resistant floating HOWWECs.

CRS_PolyU505/23
The Mechanism and Policy Optimisation of Multi-stakeholder Cross-regional Collaboration in the Construction Industry of the GBA

Hong Kong Project Coordinator: Prof Qiping Shen (The Hong Kong Polytechnic University)
Mainland Project Coordinator: Prof Dongping Fang (Tsinghua University)

The multi-stakeholder cross-regional collaboration (CRC) in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) construction industry is a unique form of practice in the context of ‘One Country, Two Systems’, facing multiple institutional environments featured as multi-layered, self-organised and polycentric. However, the uniqueness of CRC is confronted with challenges in the systems and mechanisms, which seriously restricts the effective development of CRC in the GBA construction industry (GBACI). There is a lack of in-depth studies that systematically explore the principles and mechanisms of CRC in the GBACI and scientifically reveal the effects of CRC policies on collaboration performance. Based on stakeholder and institutional theories, this project intends to adopt complex network analysis, collaborative game, and multi-agent modelling for the following research objectives from the perspective of collaboration entities: (1) to establish a case bank of CRC and identify the main modes and implementation paths of CRC; (2) to reveal the internal mechanisms of the selection of CRC modes and establish a decision-making model; (3) to reveal the influence mechanisms of CRC network structure on the performance of collaboration and optimise the multi-stakeholder CRC network structures; (4) to reveal the influence mechanisms of CRC interactions of stakeholders’ behaviour on the performance of collaboration and conduct collaboration policy simulation based on the intelligent simulation platform; (5) to propose a policy optimisation solution in promoting multi-stakeholder CRC in the GBACI and provide a scientific basis for improving the collaboration environment and enhancing the value of collaboration.

CRS_HKUST203/23
Multi-elemental Lone-electron-pair Cations Based Pb-free Perovskite Optoelectronics: From Materials Design, Synthesis to High-performance Devices

Hong Kong Project Coordinator: Dr Yuan-yuan Zhou (Hong Kong Baptist University)
Mainland Project Coordinator: Prof Lijun Zhang (Jilin University)

Perovskite solar cells (PSCs) have emerged as a promising photovoltaic technology for integration into the future urban environment to power buildings and internet of things (IoT) devices. However, state-of-the-art PSCs contain toxic Pb, restricting the commercialization, while as-reported Pb-free PSCs suffer from the performance and stability issues due to the intrinsic materials shortcomings. This project proposes a multi-elemental strategy to design novel Pb-free perovskites based on lone-electron-pair cations for stable, efficient Pb-free PSCs and optoelectronics.

The field has been searching for Pb-free perovskite alternatives. As of now, potentially less toxic metal cations, including Sn, Ge, Ti, Bi, Sb, etc., have been used as Pb substitutes in perovskites, respectively. Amongst these options, Sn perovskite demonstrates the highest promise, but it still suffers from the high sensitivity to oxygen. Vast efforts have been devoted to modifying Sn perovskites, and other single- or dual-cation Pb-free perovskites. But the advancements so far have not brought sufficient excitement, calling for the re-design, exploration, and discovery of a new Pb-free perovskite system from a different perspective. Therefore, we propose to examine and discover new promising candidates amongst the multi-elemental Pb-free perovskites, considering: (i) the multi-elemental strategy largely expands the chemical space for structural and property explorations; (ii) the syngenetic effects of tailoring structural factors (tolerance factor, octahedral factor), alloying ratio, and electronic dimensionality can possibly create new materials states, which can be driven by the high entropy and cation transmutation.

The project is built upon the research strengths on perovskite synthesis and characterization (ZHOU), materials design and screening (ZHANG), interface chemistry (JEN), and Pb-free devices (WANG). Interrelated tasks will be performed that will address the following three objectives: (1) Theoretical identification of multi-elemental Pb-free perovskites based on lone-pair electron cations via DFT-based and machine-learning-aided computational modeling; (2) Experimental discovery of promising perovskite candidates with high stability and optoelectronic properties via innovative synthesis and characterization; (3) Attainment of high-performance multi-elemental Pb-free perovskite devices based on the discovered perovskites and their microstructural/interface engineering.

By leveraging the strong existing research and collaboration foundations, as well as considering the vast space amongst the proposed multi-elemental Pb-free perovskite system, the progress of the proposed project can be ensured with continuous fundamental discoveries and technology innovations. These project outcomes will impart impacts not only for developing high-performance devices for real-world applications, but also for unravelling new semiconductor sciences.

CRS_HKUST404/23
Monolithic Tunable Lasers by Direct Heteroepitaxy of III-V on Silicon for Wafer-scale Photonic Integration

Hong Kong Project Coordinator: Prof Kei-may Lau (The Chinese University of Hong Kong)
Mainland Project Coordinator: Prof Daoxin Dai (Zhejiang University)

The phenomenal growth of the internet has led to enormous increases in the data transmission capacity required within data centers, which demand millions of optical components for the short reach optical interconnects. The massive optical transceivers used in datacenters makes it essential for lowering their cost. Silicon photonics has offered the solution for cost-reduction of integrated optical transceivers in data centers but does not yet offer desirable low cost because of the lack of efficiently integrated tunable lasers essential to integrated photonics. Silicon photonics makes use of fabrication process technologies and supply chain infrastructure developed for microelectronics. Benefitting from the huge investment in microelectronics, silicon photonic chips can in principle be manufactured at costs comparable to electronic chips. However, the high-cost of incorporating an advanced III-V tunable laser on silicon is yet to be addressed.

To tackle the issue of integrating tunable lasers into Si photonics, we propose to take on the challenges in materials engineering with process integration involving metalorganic chemical vapor deposition (MOCVD) of high-quality and large areas of III-V semiconductors directly on silicon substrates. Using the Lateral Aspect Ratio Trapping (LART) technique pioneered by the principal investigator, our first objective is to make electrically pumped III-V laser based on heteroepitaxial growth of III-V semiconductors on silicon-on-insulator (SOI) wafers, aligned in height with the silicon waveguides by suitable pre-patterning of the SOI wafer. This will enable direct coupling between the III-V gain waveguide and the silicon waveguide efficiently. To support lasing in the 1550nm optical communications band, we shall incorporate quantum wells (QWs) for the gain section, to be butt-coupled with the Si waveguide. The laser tuning element will be implemented by the integration of silicon photonic resonators and integrated optical filters. We shall introduce innovative new photonic structures to suppress optical reflections at the interface between the III-V gain element and the silicon waveguide. Wavelength tuning of the electrically pumped III-V optical gain element will be achieved by tuning the optical feedback from silicon waveguide tunable filters. Integrated phase shifters for lasers are continuously tunable, without longitudinal mode hopping. Our objective is to create the world’s first heteroepitaxial integrated III-V on silicon tunable laser that can address the growing demand for low-cost and large-volume manufactured tunable lasers for next generation of high-capacity short-reach optical interconnects and emerging applications such as hand-held optical coherence tomography systems and LIDAR systems.

CRS_HKUST601/23
Bound States in the Continuum (BICs) Realized in Photonic and Acoustic Crystals: Theory and Experiment

Hong Kong Project Coordinator: Prof Che-ting Chan (The Hong Kong University of Science and Technology)
Mainland Project Coordinator: Prof Lei Shi (Fudan University)

A bound state in the continuum (BIC) refers to a remarkable phenomenon where a potential well can trap a positive energy state that, in principle, can interact with the free states in the surrounding environment. The presence of a BIC is analogous to creating a bucket capable of holding water above its rim without any leakage. This intriguing phenomenon possesses numerous properties that render it highly useful. For instance, BIC states exhibit an almost infinite lifetime even when coupled to open systems. They possess the ability to confine both light and wave energy. In the field of optics, their extended lifetime and narrow linewidths offer significant advantages such as enabling lasing and sensing. Ultra-thin photonic structures that exhibit BICs can serve as optical components for manipulating waves and their polarizations. The objective of this project is to gain a deeper understanding of the existence, formation, and robustness of BICs in optical and acoustic systems. Additionally, we aim to investigate the effects of perturbations on these states. Rather than solely focusing on identifying BIC "points," we will adopt a broader perspective by considering the photonic structures that harbour BICs as systems. By doing so, we hope to uncover novel phenomena and explore new applications in the realms of light and sound that may emerge from these systems.

CRS_HKU705/23
Mechanistic Study of the Parental Histone Recycling at Replication Forks

Hong Kong Project Coordinator: Dr Yuanliang Zhai (The University of Hong Kong)
Mainland Project Coordinator: Prof Ning Gao (Peking University)

Replication of the eukaryote genome must be coupled to the faithful replication of the epigenome encoded in the post-translational modified histones for progeny cells to carry on. Extensive studies have demonstrated that the replisome, together with other factors, is necessary to dismantle the nucleosome ahead of the fork and redeposit the histone H3-H4 tetramer at the same locations on either one of the replicated strands while H2A-H2B is redistributed as dimers. Despite years of efforts, the replication-coupled mechanisms that regulate nucleosome disassembly and subsequent histone recycling remain poorly understood, especially at a molecular level.

This NSFC/RGC collaborative research project aims to take advantage of the fruitful partnership between Beijing and Hong Kong to investigate the molecular roles of FACT (facilitates chromatin transcription) in regulating replication-coupled histone recycling using our complementary multidisciplinary expertise. Our team will exploit biochemistry, structural biology, chemical biology, and proteomics approaches to capture snapshots of FACT in the act of shuffling histone transfer at replication forks. The specific roles of various factors involved in this process will be further characterized in yeast cells accordingly. The outcomes of the proposed research are expected to deliver extensive insights into chromatin replication, providing a structural framework for understanding and combating associated human diseases.