Solar cell and perovskites
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. 



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 devises

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


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).



Anna Dávid, Julia Morat, Mengyun Chen, Feng Gao, Mats Fahlman, Xianjie Liu (2024) Mapping Uncharted Lead-Free Halide Perovskites and Related Low-Dimensional Structures Materials, Vol. 17, Article 491 Continue to DOI
Yuxuan Xiao, Qin Xue, Xiaoke Liu, Feng Gao, Guohua Xie (2024) Lead-free perovskite LEDs powered by cyanuric acid INNOVATION, Vol. 5, Article 100553 Continue to DOI
Jiajia Suo, Bowen Yang, Edoardo Mosconi, Dmitry Bogachuk, Tiarnan A. S. Doherty, Kyle Frohna, Dominik J. Kubicki, Fan Fu, Yeonju Kim, Oussama Er-Raji, Tiankai Zhang, Lorenzo Baldinelli, Lukas Wagner, Ayodhya N. Tiwari, Feng Gao, Andreas Hinsch, Samuel D. Stranks, Filippo De Angelis, Anders Hagfeldt (2024) Multifunctional sulfonium-based treatment for perovskite solar cells with less than 1% efficiency loss over 4,500-h operational stability tests Nature Energy Continue to DOI
Fanglong Yuan, Giulia Folpini, Tianjun Liu, Utkarsh Singh, Antonella Treglia, Jia Wei Melvin Lim, Johan Klarbring, Sergey Simak, Igor Abrikosov, Tze Chien Sum, Annamaria Petrozza, Feng Gao (2024) Bright and stable near-infrared lead-free perovskite light-emitting diodes Nature Photonics Continue to DOI


Tianjun Liu, Feng Gao (2023) Molecule additive design for perovskite light-emitting diodes operated at high current densities Chem, Vol. 9, p. 2058-2059 Continue to DOI
Tiefeng Liu, Johanna Heimonen, Qilun Zhang, Chiyuan Yang, Jun-Da Huang, Hanyan Wu, Marc-Antoine Stoeckel, Tom van der Pol, Yuxuan Li, Sang Young Jeong, Adam Marks, Xin-Yi Wang, Yuttapoom Puttisong, Asaminew Yerango Shimolo, Xianjie Liu, Silan Zhang, Qifan Li, Matteo Massetti, Weimin Chen, Han Young Woo, Jian Pei, Iain McCulloch, Feng Gao, Mats Fahlman, Renee Kroon, Simone Fabiano (2023) Ground-state electron transfer in all-polymer donor:acceptor blends enables aqueous processing of water-insoluble conjugated polymers Nature Communications, Vol. 14, Article 8454 Continue to DOI
G. Krishnamurthy Grandhi, David Hardy, Mokurala Krishnaiah, Brenda Vargas, Basheer Al-Anesi, Mahesh P. Suryawanshi, Diego Solis-Ibarra, Feng Gao, Robert L. Z. Hoye, Paola Vivo (2023) Wide-Bandgap Perovskite-Inspired Materials: Defect-Driven Challenges for High-Performance Optoelectronics Advanced Functional Materials Continue to DOI
Lucy J. F. Hart, Jeannine Gruene, Wei Liu, Tsz-ki Lau, Joel Luke, Yi-Chun Chin, Xinyu Jiang, Huotian Zhang, Daniel J. C. Sowood, Darcy M. L. Unson, Ji-Seon Kim, Xinhui Lu, Yingping Zou, Feng Gao, Andreas Sperlich, Vladimir Dyakonov, Jun Yuan, Alexander J. J. Gillett (2023) Understanding the Role of Triplet-Triplet Annihilation in Non-Fullerene Acceptor Organic Solar Cells Advanced Energy Materials, Vol. 13, Article 2301357 Continue to DOI
Wei Liu, Huotian Zhang, Songting Liang, Tong Wang, Siqing He, Yunbin Hu, Rui Zhang, Haoqing Ning, Jie Ren, Artem Bakulin, Feng Gao, Jun Yuan, Yingping Zou (2023) The Synthesis of a Multiple D-A Conjugated Macrocycle and Its Application in Organic Photovoltaic Angewandte Chemie International Edition Continue to DOI
Jian Qing, Sankaran Ramesh, Xiaoke Liu, Heyong Wang, Hongling Yu, Chaoyang Kuang, Lintao Hou, Wenjing Zhang, Tze Chien Sum, Feng Gao (2023) Spacer cation engineering in Ruddlesden-Popper perovskites for efficient red light-emitting diodes with recommendation 2020 color coordinates Applied Surface Science, Vol. 616, Article 156454 Continue to DOI
Hongru Chen, Zhi-Guo Zhang, Feng Gao (2023) Solidification of solvent additive for stable binary polymer solar cells with similar to 19% efficiency SCIENCE CHINA-MATERIALS, Vol. 66, p. 2523-2524 Continue to DOI
Fuxiang Ji, Johan Klarbring, Bin Zhang, Feng Wang, Linqin Wang, Xiaohe Miao, Weihua Ning, Muyi Zhang, Xinyi Cai, Babak Bakhit, Martin Magnuson, Xiaoming Ren, Licheng Sun, Mats Fahlman, Irina A Buyanova, Weimin Chen, Sergei I Simak, Igor A. Abrikosov, Feng Gao (2023) Remarkable Thermochromism in the Double Perovskite Cs2NaFeCl6 Advanced Optical Materials, Article 2301102 Continue to DOI
Zhan Chen, Xiaoke Liu, Heyong Wang, Xianjie Liu, Lintao Hou, Feng Gao (2023) Photoluminescence Enhancement for Efficient Mixed-Halide Blue Perovskite Light-Emitting Diodes Advanced Optical Materials, Vol. 11, Article 2202528 Continue to DOI
Bin Zhang, Yuqing Huang, Fuxiang Ji, Xiaohe Miao, Feng Gao, Weimin Chen, Irina Buyanova (2023) Photoactivated Second Harmonic Generation in Centrosymmetric Double Perovskites ACS Photonics, Vol. 10, p. 3350-3358 Continue to DOI
Xiangyang Fan, Yu Wang, Xinyu Shen, Zhongkai Yu, Woo Hyeon Jeong, Ji Won Jang, Yeong Gyeong Kim, Seung-Je Woo, Hyungju Ahn, Hyosung Choi, Tae-Woo Lee, Sung Heum Park, Feng Gao, Bo Ram Lee (2023) Phosphine oxide modulator-ameliorated hole injection for blue perovskite light-emitting diodes Journal of Materials Chemistry A, Vol. 11, p. 20808-20815 Continue to DOI


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. 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.