Optoelectronics

Solar cell and perovskites
Photographer: Olov Planthaber

We are a multidisciplinary team focusing on solution-processed optoelectronic materials and devices, with a passion for both fundamental science and new applications of these materials and devices.

Optoelectronic devices, such as light-emitting diodes (LEDs), solar cells, photodetectors, lasers and optical transmitters and receivers, are an important part in maintaining a sustainable world. The emergence of exceptional solution-processed semiconductors, including organic semiconductors and metal halide perovskites, offers great opportunities for developing new generations of optoelectronic devices that are of high performance, cost-effective, and integrable with other technological systems.

We have developed a worldwide professional network for collaborations and are also actively engaging in collaborations with industry partners.


News

Huotian Zhang

Huotian Zhang receives royal scholarship for his solar energy research

For the second year in a row, a researcher at the Division of Optoelectronics at Linköping University, has been awarded the prestigious scholarship from Stiftelsen Konung Carl XVI Gustafs 50-årsfond för vetenskap, teknik och miljö.

Portrait (Feng Gao).

Prestigious physics award for Feng Gao

This year's Göran Gustafsson Prize in Physics goes to LiU professor Feng Gao. His research focuses on how new materials can be used for the next generation of solar cells and LEDs, among other things. The total prize money is SEK 7.5 million.

Researcher hold a glowing sheet of glass with tweezers.

Next generation LEDs are cheap and sustainable

Cost, technical performance and environmental impact – these are the three most important aspects for a new type of LED technology to have a broad commercial impact on society. This has been demonstrated by LiU-researchers in a new study.

Materials

Organic semiconductors

Organic semiconductors have great potential in low-cost and large-area device applications, benefiting from cheap manufacturing processes such as solution-based roll-to-roll printing.
All device applications previously dominated by inorganic semiconductors have presented opportunities for their organic counterparts. Such applications include solar cells, LEDs, field-effect transistors, lasers, and memory devices.

Metal halide perovskites

Metal halide perovskites have emerged as one of the most popular semiconducting materials since 2009. They have shown unique properties, including:

Tunable bandgap

High absorption coefficient

Broad absorption spectrum

High charge carrier mobility

Long charge diffusion lengths

These properties enable metal halide perovskites to be used in a broad range of photovoltaics and other optoelectronic applications.

Lead free perovskites /Lead free metal halides

The state-of-the-art halide perovskites used for high-performance optoelectronic devices contain toxic lead (Pb). It is therefore attractive to develop lead free perovskites or perovskite alike materials with as good properties as the lead containing counterparts. These new materials provide a rich library to investigate fundamental optoelectronic properties and bring about new possibilities to explore the spintronic properties (e.g. when magnetic ions are involved).

Optoelectronic devices

Organic solar cell with the aktive layer Pm6:Y6Organic solar cell with the aktive layer Pm6:Y6 Photo credit Olov PlanthaberSolar cells

Solar power is an ideal source for renewable and clean energy. Solar cells are semiconducting devices which can directly convert solar energy into electricity. 
The current solar cell market is dominated by silicon-based devices, with just over 2% of global electricity coming from solar in 2019. The emerging solution-processed solar cells based on organic semiconductors and metal halide perovskites have shown great potential to significantly promote the widespread use of the solar cell technology owing to their advantages of both high performance and low cost. 

Perovskite quantum dotsPerovskite quantum dots Photo credit Olov PlanthaberLEDs

Lighting and displays products are vital electric devices in our daily life, which also account for the largest portion of electricity consumption. LEDs are semiconductor light sources, which emit light when current flows through them. LEDs are considered the most promising energy-efficient technologies for lighting and displays.

Metal halide perovskites demonstrate strong photoluminescence and tunable emission colours, making them a promising candidate for the next generation of highly efficient LEDs.


A combined optical transmitter and receiverA combined optical transmitter and receiver Photo credit Magnus JohanssonOther devices

Photodetectors and optical receivers are sensors of light, which can convert light signals into electric signals. They have wide applications, such as optical communication and medical/ healthcare instruments.

Lasers are unusual light sources. They emit a very narrow beam of monochromatic light that is amplified and coherent. Lasers have a variety of applications, ranging from precision cutting tools to communications and scientific instruments.


Research and funding

Research

The Optoelectronic group lead by Prof. Gao dedicates its efforts to energy devices, with the ambition to both improve device performance and understand the underlying fundamentals. Their current investigations include organic semiconductors and metal halide perovskites, with research focuses such as:

  • Fullerene-free organic solar cells (OSCs) (see our Review article in Nature Materials). We are interested in fundamental working mechanisms of OSCs (e.g. voltage losses in Nature Energy, Nature Materials, and Nature Energy; at the same time, we also collaborate with our partners to develop OSCs towards practical applications (e.g. indoor applications of OSCs in Nature Energy, and green solvent processing of OSCs in Nature Energy).
  • Perovskite solar cells. We focus on developing stable perovskite solar cells and understanding the degradation mechanisms (e.g. stable perovskite solar cells in Nature)
  • Perovskite LEDs (see our Review article in Nature Materials). We aim to develop high-performance perovskite LEDs with different colours (e.g. near infrared in Nature Photonics and blue in Nature Communications), understand the mechanisms (e.g. operational mechanisms in Nature Communications, chemical interactions for high-efficiency and stable perovskite LEDs in Nature Communications and Joule), and explore new applications (e.g. bidirectional optical signal transmission in Nature Electronics)
  • Lead-free perovskites (see our Review article on lead-free double perovskites in Advanced Materials). We focus on new materials development (e.g. iron-doped double perovskites in Science Advances) and the understanding of fundamental properties (e.g. self-trapping in double perovskites in Science Advances).

Publications

2025

Ruiqin Huang, Longbo Yang, Feng Yang, Yuttapoom Puttisong, Qingsong Hu, Guixian Li, Jingnan Hu, Zhaobo Hu, Liang Li, Jiang Tang, Weimin Chen, Yibo Han, Jiajun Luo, Feng Gao (2025) Spin-polarized self-trapped excitons in low-dimensional cesium copper halide Nature Communications, Vol. 16, Article 7264 (Article in journal) Continue to DOI
Masoud Karimipour, Nil Monros Oliveras, Zhenchuan Tian, Francesco Salutari, Maria Chiara Spadaro, Tiankai Zhang, Naji Vahedigharehchopogh, Jordi Arbiol, Feng Gao, Monica Lira-Cantu (2025) Me-4PACz Functionalized MXene for Halide Perovskite Solar Cells Advanced Science (Article in journal) Continue to DOI
Zhigao Huang, Yinjuan Ren, Yiming Wu, Jiajun Qin, Kerong Jiao, Hao Zhang, Van Duong Ta, Feng Gao, Hua Shen, Yue Wang (2025) Sustained Continuous-Wave Lasing in Quantum Dot Microfluids Advanced Materials (Article in journal) Continue to DOI
Meng Cai, Wei Liu, Tiankai Zhang, Pengfei Yan, Yuxuan Li, Weiqian Kong, Hangjuan Wu, Zongwei Chen, Zhenkun Gu, Lin Dong, Qun Xu, Yanlin Song, Junjie Ma, Chongxin Shan, Feng Gao (2025) Intermediate-States Mediated 2D MoO3-x Plasmon Enabling Pure-Phased CsPbX3 Photovoltaics with 27.33% Bifacial Efficiency Advanced Materials (Article in journal) Continue to DOI
Heyong Wang, Antonella Treglia, Chun-Sheng Jack Wu, Guanhaojie Zheng, Miguel M. de Vries Ibanez, Gianvito Vile, Hui Li, Luca Gregori, Filippo De Angelis, Jianpu Wang, Feng Gao, Annamaria Petrozza (2025) In-Situ Self-Encapsulated Tin-Halide Perovskites for Air-Functional Near-Infrared Light-Emitting Diodes ACS Energy Letters, Vol. 10, p. 3375-3382 (Article in journal) Continue to DOI
Haixia Hu, Rui Zhang, Dongcheng Jiang, Xinyu Mu, Jicheng Yi, Han Yu, Lik-Kuen Ma, Bin Li, Lingxin Cao, Mengzhen Sha, Jiangkai Sun, Ruohua Gui, Wei Liu, Shijie Liang, Longlong Li, Shufen Huang, Jianyu Yuan, Chengwang Niu, Cunquan Qu, Jun Yuan, Rongkun Zhou, Chen Zhang, Lin Lu, Xiaoyan Du, Kun Gao, Weiwei Li, Shu Kong So, Yingping Zou, Yanming Sun, Xiaotao Hao, Feng Gao, He Yan, Hang Yin (2025) Revealing electron transport connectivity as an important factor influencing stability of organic solar cells Nature Communications, Vol. 16, Article 6546 (Article in journal) Continue to DOI
Guangkun Song, Tengfei He, Ruohan Wang, Yanni Ouyang, Nakul Jain, Saisai Liu, Bin Kan, Yujie Shang, Jiaqi Li, Xingkai Wang, Zhaoyang Yao, Xiangjian Wan, Chenxi Li, Wei Ma, Yan Zhao, Guankui Long, Chunfeng Zhang, Feng Gao, Yongsheng Chen (2025) Regulate the Singlet-Triplet Energy Gap by Spatially Separating HOMO and LUMO for High Performance Organic Photovoltaic Acceptors Angewandte Chemie International Edition, Article e202506357 (Article in journal) Continue to DOI
Li Wan, Eunkyung Cho, Rui Zhang, Theis Brock-Nannestad, Zhaohui Wang, Jean-Luc Bredas, Veaceslav Coropceanu, Feng Gao (2025) Giant Circularly Polarized Luminescence Driven by Excited-State Hybridization Between Molecular Emitters and Chiral Environments Advanced Materials (Article in journal) Continue to DOI
Gulzada Beket, Anton Zubayer, Leonie Pap, Huagui Lai, Samiran Bairagi, Nakul Jain, Jochen Stahn, Fan Fu, Kenneth Järrendahl, Fredrik Eriksson, Xabier Rodriguez-Martinez, Olle Inganäs, Uli Wuerfel, Thomas Osterberg, Jonas Bergqvist, Feng Gao (2025) Understanding and Addressing the Performance Asymmetry Issue in Semitransparent Laminated Organic Photovoltaic Devices Advanced Functional Materials (Article in journal) Continue to DOI
Tianxiao Liu, Zhijun Ren, Yangyang Liu, Yaoyao Zhang, Jing Liang, Fangwen Cheng, Yiran Li, Xiaoyu Shi, Yunjie Dou, Xiaodong Hu, Lingyuan Wang, Siwei Luo, Feifei Wang, Xiaoxiao Peng, Yu Zhao, Wei Wang, Yi Cao, Feng Gao, Shangshang Chen (2025) Efficient perovskite solar modules enabled by a UV-stable and high-conductivity hole transport material Science Advances, Vol. 11, Article eadu3493 (Article in journal) Continue to DOI
Yue Chen, Xiaopeng Duan, Junjie Zhang, Zhongwei Ge, Haisheng Ma, Xiaobo Sun, Huotian Zhang, Jiaxin Gao, Xuelin Wang, Xunchang Wang, Zheng Tang, Renqiang Yang, Feng Gao, Yanming Sun (2025) Reducing energy loss by developing luminescent triphenylamine functionalized electron acceptor for high performance organic solar cells Energy & Environmental Science (Article in journal) Continue to DOI
Ligang Yuan, Qifan Xue, Feng Wang, Ning Li, Geoffrey I. N. Waterhouse, Christoph J. Brabec, Feng Gao, Keyou Yan (2025) Perovskite Solar Cells and Light Emitting Diodes: Materials Chemistry, Device Physics and Relationship Chemical Reviews (Article, review/survey) Continue to DOI
Feng Gao, Samuel D. Stranks (2025) The preface: physical properties and functional behaviours of metal halide perovskites and their derivatives NATIONAL SCIENCE REVIEW, Vol. 12, Article nwaf167 (Article in journal) Continue to DOI
Junjie Zhang, Xiaopeng Duan, Xiaoming Li, Guangkuo Dai, Jiawei Deng, Xunchang Wang, Jiawei Qiao, Hanzhi Wu, Liming Liu, Haodong Huang, Sha Liu, Jun Yan, Huotian Zhang, Xiao-Tao Hao, Renqiang Yang, Feng Gao, Yanming Sun (2025) Achieving 20% efficiency in binary organic solar cells with suppressed non-radiative recombination via triphenylamine halides Energy & Environmental Science (Article in journal) Continue to DOI
Zhongcheng Yuan, Sai Bai, Feng Gao, Henry J. Snaith (2025) Influence of Interfacial Reactions on Perovskite Optoelectronic Devices Small Methods (Article, review/survey) Continue to DOI

Coworkers

Two male scientists walks and talks in a hallway.
Principal research engineer Weihua Ning and professor Feng Gao at the Department of Physics, Chemistry and Biology. Photographer: Thor Balkhed

Group and Supervision

Prof. Feng Gao is deeply involved in both the scientific and career development of his group members. The senior researchers in his group have been awarded the prestigious VR Staring Grant, Marie Skłodowska-Curie Individual Fellowship, VINNMER Fellowship.

He also values the exchange of ideas: he has sponsored members of his group in exchanges to Cambridge, Oxford and EPFL, and his group has hosted visiting students and scholars from Cambridge, Zhejiang University, Nanjing University, Nanjing Tech University, Shenzhen University, Queen Mary University of London, and more.

Contact

Organisation