Tue 11 Feb 18:30: Enterprise Tuesday: Quantum – ready or not
Quantum Computing is set to redefine the limits of what we can achieve. It is predicted to have an impact sooner rather than later and now is the time to think about its impact on your start up or organisation. This talk is chaired by Ilyas Khan, Founder and Chief Product Officer of Quantinuum. Our guest panellists are Steve Brierley, CEO , Riverlane; Phil O’Donovan, Cambridge Angel; and Dr Jeremy Sosabowski, Co-founder Executive Director, AlgoDynamix.
Register to book your place > https://www.jbs.cam.ac.uk/events/enterprise-tuesday-quantum-ready-or-not/
Quantum computing is set to redefine the limits of what we can achieve. It is predicted to have an impact sooner rather than later and now is the time to think about its impact on your start up or organisation.
Surpassing the capabilities of traditional computers, the remarkable potential of quantum computing lies in performing highly complex calculations at unprecedented speeds, paving the way for groundbreaking advancements across various sectors that will transform industries significantly.
In the healthcare field, it may accelerate the creation of innovative treatments and enhance personalised medicine. In manufacturing, it could optimise supply chains and boost production efficiency. In the energy sector, it might hasten the progress of fusion power development. And in finance, it has the potential to introduce new financial products and services while improving risk management and trading strategy models.
Quantum computing holds the promise to unlock discoveries we’ve only imagined. Join our expert panel to help you get a head start on thinking about how you will be impacted as they delve into the multi-faceted possibilities of this cutting-edge technology and the hurdles that might arise.
Register now and get ready for an evening filled with insightful conversations and networking opportunities within the Cambridge community.
Enterprise Tuesday is managed by Cambridge Judge Entrepreneurship Centre. It is open to all members of the University of Cambridge, aspiring entrepreneurs and members of the business community. The talks are free to attend, enable audiences to learn from experienced entrepreneurs and experts, and to build relationships with a high value group of like-minded individuals through the networking. Registration is essential.
- Speaker: Ilyas Khan, Founder and Chief Product Officer of Quantinuum; Steve Brierley, CEO, Riverlane; Phil O’Donovan, Cambridge Angel; and Dr Jeremy Sosabowski, Co-founder Executive Director, AlgoDynamix.
- Tuesday 11 February 2025, 18:30-21:00
- Venue: Cambridge Judge Business School, Trumpington St, CB2 1AG.
- Series: Entrepreneurship Centre at Cambridge Judge Business School; organiser: Enterprise Tuesday.
Tue 04 Feb 18:30: Enterprise Tuesday: Building resilience in entrepreneurship – why investing and developing your resilience can be a key predictor of success
In this session chaired by Sarah Mardle, CEO and Founder of Alma Business Consulting, we discuss the importance of developing resilience, viewing challenges and setbacks as opportunities for learning and growth rather than personal failures. The panellists are Mari Williams, Founder of The Mind Architect; Matthew Cleevely, Partner at Cleevely & Partners Ltd; and Rob Thomson, Flagstaff Advisory.
Register to book your place > https://www.jbs.cam.ac.uk/events/enterprise-tuesday-building-resilience-in-entrepreneurship-why-investing-and-developing-your-resilience-can-be-a-key-predictor-of-success/
Entrepreneurs and innovators, often spend considerable time focused on business model strategies, funding, and go-to-market plans, but they frequently overlook the importance of resilience. Research has consistently shown that resilience is a key predictor of entrepreneurial success and entrepreneurs with high levels of resilience were more likely to achieve their goals. Additionally, they tend to report higher levels of job satisfaction.
Entrepreneurship is a constant cycle of successes and setbacks so founders must be able to adapt in the face of constant change. Cultivating resilience is essential for entrepreneurs as it enhances the ability to navigate both the personal and professional challenges associated with starting and growing a venture. Resilient entrepreneurs are more adept at recovering from setbacks, ensuring they remain flexible and responsive.
In this session, we discuss the importance of developing resilience, viewing challenges and setbacks as opportunities for learning and growth rather than personal failures.
Enterprise Tuesday is managed by Cambridge Judge Entrepreneurship Centre. It is open to all members of the University of Cambridge, aspiring entrepreneurs and members of the business community. The talks are free to attend, enable audiences to learn from experienced entrepreneurs and experts, and to build relationships with a high value group of like-minded individuals through the networking. Registration is essential.
- Speaker: Sarah Mardle, CEO and Founder of Alma Business Consulting; Mari Williams, Founder of The Mind Architect; Matthew Cleevely, Partner at Cleevely & Partners Ltd; and Rob Thomson, Flagstaff Advisory.
- Tuesday 04 February 2025, 18:30-21:00
- Venue: Cambridge Judge Business School, Trumpington St, CB2 1AG.
- Series: Entrepreneurship Centre at Cambridge Judge Business School; organiser: Enterprise Tuesday.
Wed 12 Feb 15:05: Hardware Datapath: For Machine Learning and Beyond
Abstract: We will explore a couple of topics of recent interest to me: how to best bridge the Boolean world of hardware design with the continuous world of modern machine learning, and how to utilise recent advances in graph rewriting for datapath optimization. The former will lead us to explore how the fundamental computational units of deep learning might be reconsidered with hardware efficiency in mind. The latter will allow us to optimize hardware for computer arithmetic, including automated (re-)discovery of well-known manual tricks, and is now in use by Intel. This talk summarises the outcomes of joint work with Marta Andronic, Peter Cheung, Sam Coward, James Davis, Theo Drane and Erwei Wang.
Bio: George A. Constantinides received the Ph.D. degree from Imperial College London in 2001. Since 2002, he has been with the faculty at Imperial College London, where he is currently Professor of Digital Computation and Director of the Imperial Early Career Researcher Institute, having previously served as Associate Dean of Engineering and Head of Circuits and Systems. He has been TPC chair of the FPGA , FPL and FPT conferences. He currently serves on several program committees and has published over 200 research papers in peer refereed journals and international conferences. Prof Constantinides enjoys family, espresso and general geekery.
Link to join virtually: https://cam-ac-uk.zoom.us/j/87421957265
This talk is being recorded. If you do not wish to be seen in the recording, please avoid sitting in the front three rows of seats in the lecture theatre. Any questions asked will also be included in the recording. The recording will be made available on the Department’s webpage
This Wednesday Seminar will be followed by a Compiler Social. Please find further information and registration details at the following link: https://grosser.science/compiler-social-2025-02-12/
- Speaker: Professor George A. Constantinides - Professor of Digital Computation, Department of Electrical and Electronic Engineering, Imperial College London
- Wednesday 12 February 2025, 15:05-15:55
- Venue: Lecture Theatre 1, Computer Laboratory, William Gates Building.
- Series: Wednesday Seminars - Department of Computer Science and Technology ; organiser: Ben Karniely.
Thu 13 Feb 16:00: Quantitative microbiome profiling in health and disease.
Prof. Jeroen Raes (m) is full professor at KU Leuven since 2013 and VIB group leader since 2009. His group currently consists of 30 scientists, with expertise in bioinformatics, systems biology, clinical research and microbiology. He has a substantial track record in microbiome research and has been pioneering the analysis and integration of meta-omics datasets (metagenomics, metatranscriptomics, metaproteomics, meta-metabolomics) with environmental, clinical, host omics and dietary data. He was involved in the FP7 MetaHIT and NIH Human Microbiome Project (the latter as only European partner), which laid the foundations for the human microbiome field as it is today. Finally, his lab is performing a wide range of disease-related projects in a.o. IBD , diabetes, cancer, IBS and depression and develops novel approaches and tools for microbiome research. Jeroen Raes coordinates the Flemish Gut Flora project, a large-scale microbiome- focused population cohort in Belgium. He has received multiple awards and recognitions, among which a selection as FWO Odysseus Fellow, a Francqui Chair and selection for Cell journal’s “40 under 40” promising young scientists. His 2011 paper in Nature was selected by Science as part of their “Top 10 breakthroughs of the year 2011”.
Jeroen Raes has published >300 papers in top ranking journals such as Science (8), Nature (16), Cell (5), Nature Biotechnology (4), Nature Microbiology (7), Nature Reviews Microbiology (5), Gut (15) and PNAS (4). He has an h-factor of 95 and his work has been cited > 106.000 (ISI).
- Speaker: Prof. Jeroen Raes, Vice director, VIB-KU Leuven Center for Microbiology, Belgium
- Thursday 13 February 2025, 16:00-17:00
- Venue: Lecture Theatre, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus.
- Series: Cambridge Immunology Network Seminar Series; organiser: Ruth Paton.
Wed 07 May 15:05: Title to be confirmed
Abstract to be confirmed
Link to join virtually: https://cam-ac-uk.zoom.us/j/87421957265
This talk is being recorded. If you do not wish to be seen in the recording, please avoid sitting in the front three rows of seats in the lecture theatre. Any questions asked will also be included in the recording. The recording will be made available on the Department’s webpage
- Speaker: Dr Prakash Murali - Department of Computer Science and Technology, University of Cambridge
- Wednesday 07 May 2025, 15:05-15:55
- Venue: Lecture Theatre 1, Computer Laboratory, William Gates Building.
- Series: Wednesday Seminars - Department of Computer Science and Technology ; organiser: Ben Karniely.
Wed 12 Mar 15:05: Title to be confirmed
Abstract to be confirmed
Link to join virtually: https://cam-ac-uk.zoom.us/j/87421957265
This talk is being recorded. If you do not wish to be seen in the recording, please avoid sitting in the front three rows of seats in the lecture theatre. Any questions asked will also be included in the recording. The recording will be made available on the Department’s webpage
- Speaker: Dr Edwin Brady - School of Computer Science, University of St Andrews
- Wednesday 12 March 2025, 15:05-15:55
- Venue: Lecture Theatre 1, Computer Laboratory, William Gates Building.
- Series: Wednesday Seminars - Department of Computer Science and Technology ; organiser: Ben Karniely.
Wed 05 Mar 15:05: Title to be confirmed
Abstract to be confirmed
Link to join virtually: https://cam-ac-uk.zoom.us/j/87421957265
This talk is being recorded. If you do not wish to be seen in the recording, please avoid sitting in the front three rows of seats in the lecture theatre. Any questions asked will also be included in the recording. The recording will be made available on the Department’s webpage
- Speaker: Dr Joe Watson - Co-founder, Xaira Therapeutics
- Wednesday 05 March 2025, 15:05-15:55
- Venue: Lecture Theatre 1, Computer Laboratory, William Gates Building.
- Series: Wednesday Seminars - Department of Computer Science and Technology ; organiser: Ben Karniely.
Wed 26 Feb 15:05: Digital Money and Decentralised Finance
Abstract:
Our society is evolving towards digital payments and the elimination of physical cash. Digital alternatives to cash require trade-offs between various properties including unforgeability, traceability, divisibility, transferability without intermediaries, privacy, redeemability, control over the money supply and many more, some in conflict with each other. Since the 1980s, cryptographers have proposed a variety of clever technical solutions addressing some of these issues, but it is only with the appearance of Bitcoin, blockchain and a plethora of copycat cryptocurrencies that a new asset class has emerged, now worth in excess of three trillion dollars. This is part of an articulated decentralised finance ecosystem, where new trading platforms and innovative products are starting to impact the way financial transactions take place. Meanwhile, most major countries have been planning the introduction of Central Bank Digital Currencies in an attempt to retain control.
From our respective backgrounds in cybersecurity and financial markets, we designed a new interactive ACS M Phil module on these topics, R160 (https://www.cl.cam.ac.uk/teaching/2425/R160/), in order to encourage the students to make sense of the technical, social and economic problems and opportunities in this exciting field. We are at a historical turning point where an enterprising candidate might disrupt the status quo and truly make a difference. We particularly encourage ambitious Part II students to attend this seminar as a taster for the Part III module they could sign up to in October.
Bios:
Frank Stajano is Professor of Security and Privacy in this department, where he got his PhD, and a 5th dan martial artist in kendo, the way of the sword.
Dr. Ferdinando Samaria is a computer scientist and investment banker. He has a BA and a PhD from the Department of Engineering in Cambridge and is the author of a widely cited paper in the area of computer face recognition. After working on image processing and multimedia applications at the Olivetti Research Laboratory in the mid-90s, he moved to the City to work for Credit Suisse Financial Products. He was later hired by UniCredit as one of the founders of the Italian bank’s investment banking arm where he covered senior roles in trading and risk management. Ferdi’s current areas of interest include decentralised finance, machine learning and smart software applications for the financial industry.
Link to join virtually: https://cam-ac-uk.zoom.us/j/87421957265
This talk is being recorded. If you do not wish to be seen in the recording, please avoid sitting in the front three rows of seats in the lecture theatre. Any questions asked will also be included in the recording. The recording will be made available on the Department’s webpage
- Speaker: Professor Frank Stajano and Dr Ferdinando Samaria - Department of Computer Science and Technology, University of Cambridge.
- Wednesday 26 February 2025, 15:05-15:55
- Venue: Lecture Theatre 1, Computer Laboratory, William Gates Building.
- Series: Wednesday Seminars - Department of Computer Science and Technology ; organiser: Ben Karniely.
Wed 19 Feb 15:05: Title to be confirmed
Abstract to be confirmed
Link to join virtually: https://cam-ac-uk.zoom.us/j/87421957265
This talk is being recorded. If you do not wish to be seen in the recording, please avoid sitting in the front three rows of seats in the lecture theatre. Any questions asked will also be included in the recording. The recording will be made available on the Department’s webpage
- Speaker: Dr Ilan Price - Senior Research Scientist, Google DeepMind
- Wednesday 19 February 2025, 15:05-15:55
- Venue: Lecture Theatre 1, Computer Laboratory, William Gates Building.
- Series: Wednesday Seminars - Department of Computer Science and Technology ; organiser: Ben Karniely.
Wed 05 Feb 15:05: EU AI Act: A firsthand perspective
The talk will provide an overall introduction about the origin of the EU AI Act, the context in which the legislation evolved and its main components. Considering the high degree of complexity of the legal text, the presentation aims to break it down by offering insight into the rationale of the choices that were made and help the audience gather an initial understanding of the scope and potential impact.
Link to join virtually: https://cam-ac-uk.zoom.us/j/87421957265
This talk is being recorded. If you do not wish to be seen in the recording, please avoid sitting in the front three rows of seats in the lecture theatre. Any questions asked will also be included in the recording. The recording will be made available on the Department’s webpage
- Speaker: Gabriele Mazzini - Research Affiliate, MIT Media Lab
- Wednesday 05 February 2025, 15:05-15:55
- Venue: Lecture Theatre 1, Computer Laboratory, William Gates Building.
- Series: Wednesday Seminars - Department of Computer Science and Technology ; organiser: Ben Karniely.
Wed 12 Feb 16:00: Equality Saturation in a Real-World Machine Learning Compiler
Join us for a relaxed chat about compilers, while socializing over refreshments. Our social is open to students, academics, professional developers and really anyone interested in compilation. We welcome beginners as well as experts. Our social is an unguided space offered for you to get to know people, try out some new ideas, get feedback on your code, or pair-program on a difficult program. Come with just a paper notebook or bring your laptop to hack on some in-progress patches.
This social is traditionally organized by the LLVM community, but is open to all (potential) compiler enthusiasts. For the first time, the next Compiler Social Talk is part of the department’s Wednesday Seminar.
Equality Saturation in a Real-World Machine Learning Compiler
Machine learning (ML) compilers rely on graph-level transformations to enhance the runtime performance of ML models. However, these program transformations are often driven by manually-tuned compiler heuristics, which are quickly rendered obsolete by new hardware and model architectures. Instead, we propose the use of equality saturation. We replace such heuristics with a more robust global performance model, which accounts for downstream transformations. While this approach still requires a global performance model to evaluate the profitability of transformations,it holds significant promise for increased automation and adaptability. We address challenges in applying equality saturation on real-world ML compute graphs and state-of-the-art hardware, study different cost modeling approaches to deal with fusion and layout optimization, and tackle scalability issues that arise from considering a very wide range of algebraic optimizations. Our implementation builds on and improves the XLA compilation pipeline for CPU and GPU .
This talk is the second one in our compiler social, the first talk will be given by George Constantinides: https://talks.cam.ac.uk/talk/index/225220
Please register if you’re planning to attend: https://grosser.science/compiler-social-2025-02-12/
- Speaker: Alex Zinenko
- Wednesday 12 February 2025, 16:00-20:00
- Venue: Computer Laboratory, William Gates Building, LT1.
- Series: compiler socials; organiser: luisa.cicolini.
Thu 30 Jan 14:00: Generalizable Embodied Foundation Model
In this talk, we will start from the fundamental question of what is, how to measure, how to improve the generalization ability of deep neural networks, especially on the out-of-distribution generalization ability, where the test data distribution differs from the training data distribution. Then, we will demonstrate how to leverage the lessons from theoretical and algorithmic research for important applications, such as high dynamic range imaging, autonomous driving, control, and embodied artificial intelligence.
Zoom link: https://cam-ac-uk.zoom.us/j/83872164360?pwd=k1tXJAfe9hisCybo108WWKar8gP5Ly.1
- Speaker: Nanyang Ye, Shanghai Jiao Tong University
- Thursday 30 January 2025, 14:00-15:00
- Venue: SS03 - William Gates Building.
- Series: Rainbow Group Seminars; organiser: Rafal Mantiuk.
Thu 15 May 14:00: Walter Kohn: the theoretical physicist who created DFT and won the Nobel Prize for Chemistry
Abstract not available
- Speaker: Prof. Sir David Clary, FRS (Cambridge & Oxford)
- Thursday 15 May 2025, 14:00-15:30
- Venue: TCM Seminar Room.
- Series: Theory of Condensed Matter; organiser: Bo Peng.
Advanced carbon-based rear electrodes for low-cost and efficient perovskite solar cells
DOI: 10.1039/D4EE05462H, Review ArticleJingsheng He, Yu Bai, Zhixin (Veela) Luo, Ran Ran, Wei Zhou, Wei Wang, Zongping Shao
Perovskite solar cells (PSCs) as new-generation photovoltaic cells have received remarkable interests due to the facile fabrication procedures and superb power conversion efficiencies (PCEs). Nevertheless, the widely used noble metal-based...
The content of this RSS Feed (c) The Royal Society of Chemistry
Fri 07 Feb 13:00: Unimodular JT gravity and de Sitter quantum cosmology
In this talk, I will show how a gauge-theoretic approach to Jackiw–Teitelboim (JT) gravity naturally yields a two-dimensional Henneaux–Teitelboim (HT) unimodular theory, applicable to both flat and curved spacetimes. Under a mini-superspace reduction, the Wheeler–DeWitt equation becomes a Schrödinger-like equation admitting a consistent, unitary quantum description. The resulting wavefunction describes a quantum distribution for the scale factor, illuminating cosmic expansion and contraction, and allowing topology change at a=0.
- Speaker: Farbod Rassouli, University of Nottingham
- Friday 07 February 2025, 13:00-14:00
- Venue: Venue to be confirmed.
- Series: DAMTP Friday GR Seminar; organiser: Xi Tong.
Wed 12 Feb 16:00: Equality Saturation in a Real-World Machine Learning Compiler
Join us for a relaxed chat about compilers, while socializing over refreshments. Our social is open to students, academics, professional developers and really anyone interested in compilation. We welcome beginners as well as experts. Our social is an unguided space offered for you to get to know people, try out some new ideas, get feedback on your code, or pair-program on a difficult program. Come with just a paper notebook or bring your laptop to hack on some in-progress patches.
This social is traditionally organized by the LLVM community, but is open to all (potential) compiler enthusiasts. For the first time, the next Compiler Social Talk is part of the department’s Wednesday Seminar.
Equality Saturation in a Real-World Machine Learning Compiler
Machine learning (ML) compilers rely on graph-level transformations to enhance the runtime performance of ML models. However, these program transformations are often driven by manually-tuned compiler heuristics, which are quickly rendered obsolete by new hardware and model architectures. Instead, we propose the use of equality saturation. We replace such heuristics with a more robust global performance model, which accounts for downstream transformations. While this approach still requires a global performance model to evaluate the profitability of transformations,it holds significant promise for increased automation and adaptability. We address challenges in applying equality saturation on real-world ML compute graphs and state-of-the-art hardware, study different cost modeling approaches to deal with fusion and layout optimization, and tackle scalability issues that arise from considering a very wide range of algebraic optimizations. Our implementation builds on and improves the XLA compilation pipeline for CPU and GPU .
This talk is the second one in our compiler social, the first talk will be given by George Constantinides: https://talks.cam.ac.uk/talk/index/225220
Please register if you’re planning to attend: https://grosser.science/compiler-social-2025-02-12/
- Speaker: Speaker to be confirmed
- Wednesday 12 February 2025, 16:00-20:00
- Venue: Computer Laboratory, William Gates Building, LT1.
- Series: compiler socials; organiser: Luisa Cicolini.
Battery Lifetime Prediction Using Surface Temperature Features from Early Cycle Data
DOI: 10.1039/D4EE05179C, PaperLawnardo Sugiarto, Zijie Huang, Yi-Chun Lu
Lithium-ion batteries (LIBs) are highly sensitive to cycling conditions and show a nonlinear degradation pattern, typically noticeable in later stages. This affects the accuracy of most battery health prognostic models,...
The content of this RSS Feed (c) The Royal Society of Chemistry
Broadband Near‐Infrared Fibers Derived from Nanocrystal‐Glass Composites for Miniature Arrays Light Sources
The design synthesis of highly efficient Cr3+-doped broadband near-infrared (NIR) nanocrystal-glass composite (NGC) and the following NGC fiber fabrication for the miniature array light sources is innovated, facilitating the convergence of fluorescence imaging and all-fiber endoscopy systems.
Abstract
Broadband near-infrared (NIR) fiber arrays are highly desirable for multiplexed fluorescence endoscopic, however, there is a challenge for the development of miniature light sources with highly efficient broadband NIR emissions. Here the synthesis of a MgAl2O4:Cr3+ nanocrystal-glass composite (NGC) with an Cr3+-clusters-induced broadband NIR emission possessing is presented and external quantum efficiency of 44% and a full width at half maximum of 297 nm, and the NGC fiber is further fabricated through a template solidification strategy, resulting in the construction of an all-fiber coupling system by fusing them with commercial quartz fiber that achieves an optical coupling efficiency of 95.2%. Furthermore, these NGC fibers are regularly arranged into fiber bundle as an array light source to enhance NIR luminescence and imaging ability, and the fluorescence imaging of 4 mm biological tissue penetration is realized, as well as the multiplexed fluorescence imaging, under the irradiation of the NIR fiber bundle. This study provides general and efficient fiber fabrication guidelines toward NIR array light sources, opening the new routes for fluorescence endoscopes.
Vertical Memristive Crossbar Array for Multilayer Graph Embedding and Analysis
To address the challenge of embedding multilayer graphs with minimal complexity and information loss, this study introduces a vertical m-CBA (vm-CBA) capable of directly mapping multilayer relationships. By accurately representing inter-layer and intra-layer connections in three dimensions, vm-CBA outperforms conventional embeddings in link prediction and information scores while requiring fewer operations.
Abstract
Graph data structures effectively represent objects and their relationships, enabling the modeling of complex connections in various fields. Recent work demonstrate that metal at diagonal crossbar arrays (m-CBA) can effectively represent planar graphs. However, they are unsuitable for representing multilayer graphs having multiple relationships across different layers. Using conventional software, embedding multilayer graphs in high-dimensional Euclidean spaces introduces significant mathematical complexity and computational burden, often resulting in information loss. This study proposes a unique graph embedding (mapping) method utilizing a fabricated vertical m-CBA (vm-CBA), where a custom-built measurement system thoroughly validated its functionality. This structure directly maps multilayer graphs into a 3D vm-CBA, accurately representing inter-layer and intra-layer connections. The practical link prediction and information scores across various real-world datasets demonstrated that vm-CBA achieved enhanced accuracy compared to conventional embeddings, even with a significantly decreased number of operations.
Synergistic Hybrid‐Ligand Passivation of Perovskite Quantum Dots: Suppressing Reduced‐Dimensionality and Enhancing Optoelectronic Performance
The generation and phase transition of reduced dimensional perovskites triggered by phenethylammonium iodide deteriorates the structural and optical properties of CsPbI3-perovskite quantum dots (PQDs). Triphenylphosphine oxide, introduced as an ancillary ligand, not only suppresses the phase transition but also further passivates the trap sites on the CsPbI3-PQDs, leading to improved device performance in CsPbI3-PQD-based light-emitting diode and solar cell devices.
Abstract
In terms of surface passivation for realizing efficient CsPbI3-perovskite quantum dot (CsPbI3-PQD)-based optoelectronic devices, phenethylammonium iodide (PEAI) is widely used during the ligand exchange. However, the PEA cation, due to its large ionic radius incompatible with the 3D perovskite framework, acts as an organic spacer within polycrystalline perovskites, leading to the formation of reduced dimensional perovskites (RDPs). Despite sharing the identical 3D perovskite framework, the influence of PEAI on the structure of CsPbI3-PQDs remains unexplored. Here, it is revealed that PEAI can induce the formation of high-n RDPs (n > 2) within the CsPbI3-PQD solids, but these high-n RDPs undergo an undesirable phase transition to low-n RDPs, leading to the structural and optical degradation of CsPbI3-PQDs. To address the PEAI-induced issue, we employ triphenylphosphine oxide (TPPO) as an ancillary ligand during the ligand exchange process. The incorporation of TPPO prevents H2O penetration and regulates the rapid diffusion of PEAI, suppressing the formation of low-n RDPs. Moreover, TPPO can passivate the uncoordinated Pb2+ sites, reducing the nonradiative recombination. This hybrid-ligand exchange strategy using both PEAI and TPPO enables realizing efficient and stable CsPbI3-PQD-based light-emitting diode (external quantum efficiency of 21.8%) and solar cell (power conversion efficiency of 15.3%) devices.