Rational Ion Migration Management for Long-Term Stable Blue Perovskite Light-Emitting Diodes
Lead Research Organisation:
UNIVERSITY OF OXFORD
Department Name: Oxford Physics
Abstract
Metal halide perovskites, which possess high conductivity, high photoluminescence quantum efficiency and color purity, are ideal emitters for cost-effective light-emitting diodes (LEDs). Although EQEs of perovskite LEDs (PeLEDs) emitting in red and green have been boosted to over 25 % recently, approaching that of prevailing OLED and QLEDs, it is still a great challenge to achieve high efficiency blue PeLEDs. More importantly, overcoming poor operational lifetime of PeLEDs (around 10 hours for blue PeLEDs), which is thought to originate from severe ion migration induced by electric field in perovskite emitters and interfacial degradation, is a key for further development of PeLEDs and future applications in displays and lighting.
The objective of RAIMM is achieving pure blue PeLEDs (emitting from 465 to 475 nm) with EQEs exceeding 20 % and significantly improved lifetime over 1,000 hours @100 cd/m2. My strategies are using several powerful characterizations (e.g., in-situ PL, in-situ EL imaging, PL&EL, etc.) to reveal a clear degradation mechanism of perovskite emitters and PeLEDs. Accordingly, I will introduce different processing additives to achieve highly emissive perovskite emitters with much suppressed ion migration. With the stable perovskite emitters, new device structures will be designed to stabilize the interfacial contacts and decrease turn-on voltages of PeLEDs. This strategy will minimize the electrical fields across the PeLEDs and limit ion penetration through charge transporting layers. Finally, I will be able to achieve high efficiency pure blue PeLEDs with lifetime over 1,000 h, representing a milestone in PeLEDs community. I will collaborate with Helio Display Materials to demonstrate the first all perovskite-based prototype display with Rec. 2020 color gamut. I believe our results will dramatically accelerate the progress of PeLEDs and stimulate further breakthroughs in other perovskite optoelectronic devices.
The objective of RAIMM is achieving pure blue PeLEDs (emitting from 465 to 475 nm) with EQEs exceeding 20 % and significantly improved lifetime over 1,000 hours @100 cd/m2. My strategies are using several powerful characterizations (e.g., in-situ PL, in-situ EL imaging, PL&EL, etc.) to reveal a clear degradation mechanism of perovskite emitters and PeLEDs. Accordingly, I will introduce different processing additives to achieve highly emissive perovskite emitters with much suppressed ion migration. With the stable perovskite emitters, new device structures will be designed to stabilize the interfacial contacts and decrease turn-on voltages of PeLEDs. This strategy will minimize the electrical fields across the PeLEDs and limit ion penetration through charge transporting layers. Finally, I will be able to achieve high efficiency pure blue PeLEDs with lifetime over 1,000 h, representing a milestone in PeLEDs community. I will collaborate with Helio Display Materials to demonstrate the first all perovskite-based prototype display with Rec. 2020 color gamut. I believe our results will dramatically accelerate the progress of PeLEDs and stimulate further breakthroughs in other perovskite optoelectronic devices.
Publications
Bao C
(2024)
A multifunctional display based on photo-responsive perovskite light-emitting diodes
in Nature Electronics
Hu S
(2025)
Steering perovskite precursor solutions for multijunction photovoltaics.
in Nature
| Description | In this award, we achieved photo-responsive light-emitting diodes (LEDs) that can be used both for display information and light detection, which is difficult to achieve with conventional display technologies. We further prepared a multifunctional display that uses photo-responsive metal halide perovskite LEDs as pixels. The display can be simultaneously used as a touch screen, ambient light sensor and image sensor (including for fingerprint drawing) without integrating any additional sensors. The light-to-electricity conversion efficiency of the pixels also allow the display to act as a photovoltaic device that can charge the equipment. |
| Exploitation Route | The findings in this work will be promising for developing consumer electronics, including smartphones, tablets, and wearables for touch sensing, fingerprint recognition, and health monitoring (e.g., heart rate via PPG). In addition, they can be used for self-powered displays for smartwatches and IoT devices, leveraging ambient light harvesting to extend battery life. |
| Sectors | Chemicals Digital/Communication/Information Technologies (including Software) Energy Manufacturing including Industrial Biotechology |
| Description | Interfacial Energetics Reversal Strategy for Efficient Perovskite Solar Cells |
| Organisation | East China Normal University (ECNU) |
| Country | China |
| Sector | Academic/University |
| PI Contribution | We collaborated with collegaues from Sweden and China to developed a method to change the energy level of perovskite films surface, and achieved drmatically improved device power conversion efficiency of 25.9%. We primariy contributed to the energy loss analysis of the solar cells device. |
| Collaborator Contribution | Our collaborators in Linkoping university are experts on energy level characterization and analysis and elements analysis, their works provided the critical support on this collaboration. |
| Impact | The publication from this collaboration is undereviewing in a journal. |
| Start Year | 2024 |
| Description | Interfacial Energetics Reversal Strategy for Efficient Perovskite Solar Cells |
| Organisation | Linkoping University |
| Country | Sweden |
| Sector | Academic/University |
| PI Contribution | We collaborated with collegaues from Sweden and China to developed a method to change the energy level of perovskite films surface, and achieved drmatically improved device power conversion efficiency of 25.9%. We primariy contributed to the energy loss analysis of the solar cells device. |
| Collaborator Contribution | Our collaborators in Linkoping university are experts on energy level characterization and analysis and elements analysis, their works provided the critical support on this collaboration. |
| Impact | The publication from this collaboration is undereviewing in a journal. |
| Start Year | 2024 |
| Description | Multifunctional perovskite displays |
| Organisation | Linkoping University |
| Country | Sweden |
| Sector | Academic/University |
| PI Contribution | I had designed an optoelectronic device structure that capable to operate both as a solar cell and a LEDs. With this unique property, the proof concept display based on this display showed a serial of fucntions, including as a touch screen, ambient light sensor and image sensor (including for fingerprint drawing) without integrating any additional sensors. The light-to-electricity conversion efficiency of the pixels also allow the display to act as a photovoltaic device that could charge the equipment to increase operational lifetime. |
| Collaborator Contribution | Our partners in Linkoping helped design the multifunction display and did conprehensive study of the device performance as a photodetector. Our partners in Nanjing helped to conduct device optimization and materiasl quality characterization. |
| Impact | We filed a patent on this multifunctional devices. The paper combine expertise from materials science, optoelectronics, electrical engineering, photovoltaics, human-computer interaction, biomedical engineering, energy storage, device fabrication, and computer science. This interdisciplinary approach is essential for developing advanced technologies like multifunctional displays, which require the integration of multiple functionalities into a single device. The collaboration of these fields enables the authors to push the boundaries of display technology and open up new possibilities for future applications. |
| Start Year | 2024 |
| Description | Multifunctional perovskite displays |
| Organisation | Nanjing Tech University |
| Country | China |
| Sector | Academic/University |
| PI Contribution | I had designed an optoelectronic device structure that capable to operate both as a solar cell and a LEDs. With this unique property, the proof concept display based on this display showed a serial of fucntions, including as a touch screen, ambient light sensor and image sensor (including for fingerprint drawing) without integrating any additional sensors. The light-to-electricity conversion efficiency of the pixels also allow the display to act as a photovoltaic device that could charge the equipment to increase operational lifetime. |
| Collaborator Contribution | Our partners in Linkoping helped design the multifunction display and did conprehensive study of the device performance as a photodetector. Our partners in Nanjing helped to conduct device optimization and materiasl quality characterization. |
| Impact | We filed a patent on this multifunctional devices. The paper combine expertise from materials science, optoelectronics, electrical engineering, photovoltaics, human-computer interaction, biomedical engineering, energy storage, device fabrication, and computer science. This interdisciplinary approach is essential for developing advanced technologies like multifunctional displays, which require the integration of multiple functionalities into a single device. The collaboration of these fields enables the authors to push the boundaries of display technology and open up new possibilities for future applications. |
| Start Year | 2024 |
| Description | Multifunctional perovskite displays |
| Organisation | Nanjing University (NJU) |
| Country | China |
| Sector | Academic/University |
| PI Contribution | I had designed an optoelectronic device structure that capable to operate both as a solar cell and a LEDs. With this unique property, the proof concept display based on this display showed a serial of fucntions, including as a touch screen, ambient light sensor and image sensor (including for fingerprint drawing) without integrating any additional sensors. The light-to-electricity conversion efficiency of the pixels also allow the display to act as a photovoltaic device that could charge the equipment to increase operational lifetime. |
| Collaborator Contribution | Our partners in Linkoping helped design the multifunction display and did conprehensive study of the device performance as a photodetector. Our partners in Nanjing helped to conduct device optimization and materiasl quality characterization. |
| Impact | We filed a patent on this multifunctional devices. The paper combine expertise from materials science, optoelectronics, electrical engineering, photovoltaics, human-computer interaction, biomedical engineering, energy storage, device fabrication, and computer science. This interdisciplinary approach is essential for developing advanced technologies like multifunctional displays, which require the integration of multiple functionalities into a single device. The collaboration of these fields enables the authors to push the boundaries of display technology and open up new possibilities for future applications. |
| Start Year | 2024 |
| Title | MULTIFUNCTIONAL OPTOELECTRONIC DEVICE |
| Description | The present inventon relates to a multifunctional optoelectronic device (10) comprising at least one photo-responsive perovskite light-emitting diode (LED, 1) arranged to alternatingly operate in emission mode and sensing mode. The at least one perovskite LED (1) comprises a cathode (2), an electron transport layer (ETL, 3) having a lowest unoccupied molecular orbital (LUMO) level and a highest occupied molecular orbital (HOMO) level, a perovskite layer (4) having a conduction band (CB) and a valence band (VB), a hole transport layer (HTL, 5) having a LUMO level and a HOMO level, and an anode (6). The LUMO level of the ETL (3) is lower than the CB bottom of the perovskite layer, and the HOMO level of the HTL (5) is higher than the VB top of the perovskite layer (4). The multifunctional device (10) further comprises a sensing circuit comprising a sensor arranged to determine the electric current through the at least one perovskite LED (1) and a switch arranged to select between the emission mode and the sensing mode of the perovskite LED (1) as a function of the electric current through the at least one perovskite LED (1). |
| IP Reference | WO2023149831 |
| Protection | Patent / Patent application |
| Year Protection Granted | 2023 |
| Licensed | No |
| Title | multifunctional display |
| Description | We have reported a multifunctional display based on photo-responsive PeLEDs. The display can work as a touch screen, ambient light sensor and image sensor (including fingerprint drawing, which indicates promise as a fingerprint sensor). Such integration of different functions could be used to simplify the structure and decrease the cost of display modules, and could allow ultra-thin and light-weight displays to be created. |
| Type Of Technology | Physical Model/Kit |
| Year Produced | 2023 |
| Impact | This multifunctional display is a proof concept devices and have not been used. This multifunctional display demo show that the high photoresponsivity of the pixels makes the display screen a potential platform for human-machine interactions.Our results illustrate the unique advantages of PeLEDs for display applications and offer a promising route for the development of ultra-thin, multifunctional displays. |
| Description | physics Lab to Life day |
| Form Of Engagement Activity | Participation in an open day or visit at my research institution |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Schools |
| Results and Impact | Oxford Physics is gearing up to host our annual public engagement event, Lab to Life, which aims to demonstrate how the research we do and the technologies we develop, can impact people's lives for the better. We were organizing a visit activities in our group and offered a vicit in our lab for middle school students and their parents. we showed them the cleanroom environment and how to make a solar cell or LEDs devices in the lab. Following this, we also show them one of the national facities-National Thin-Film Cluster Facility and give a short demo how future solar cells could be produced in large scale. All the students and their parents became more interested in our research works and would like to read more of our works. |
| Year(s) Of Engagement Activity | 2024 |