Energy Harvesting Devices: Solar Cells and Artificial Photosynthesis(AP)

There is a growing drive towards reducing energy demand in the UK and worldwide, with special emphasis on harvesting the light from the sun. Our group (in collaboration with the leading Chemists) is developing new materials and devices to efficiently harvest this sunlight to produce either electricity or Fuel.  Currently, we are working on perovskite solar cells (PSCs) and organic Photovoltaics(OPVs). Apart from solar cells,  we are also developing novel, environmentally friendly materials and heterojunction structures to improve the efficiency of artificial photosynthesis (solar fuel production and carbon capture).

 

Selected Publications
  1. Huang et al., Advanced Functional Materials, 2025, 2502152. https://doi.org/10.1002/adfm.202502152
  2. Raïssi et al., Advanced Materials Technologies, 2024, 9, 2400637
  3. Webb et al., Advanced Energy Materials, 2022, 12, 2200666.
  4. Li et al., Nano Energy, 2020, 78, 105249
  5. Sajjad et al., J. Mater. Chem. A, 2020, 8, 15687-15694

Photo-Assisted Rechargeable Batteries

Batteries are essential for a cleaner, greener energy future, but they still face significant challenges. For example, they often have limited lifespans, are expensive to produce and recycle, and can harm the environment during raw material extraction. We are working to develop better, more sustainable batteries that can be recharged directly using light. Current light-rechargeable batteries are inefficient, have limited lifespans, and are costly to manufacture and recycle. To overcome these challenges, we are using a specialised automated (operando) microscopy tool to monitor how batteries function and degrade in real time. By understanding the mechanisms behind battery degradation, we can optimise performance through doping, incorporating performance-enhancing additives, or creating entirely new materials, such as advanced 2D nanostructured composites, using a fast, eco-friendly process. Our ultimate goal is to develop batteries that store more energy, last longer, charge faster, and are cheaper and easier to produce.

Patent
  1. R. Khatoon, S. Dunn, M. T. Sajjad, Photoelectrodes (GB2503090.9), 2025.

Selected Publications
  1. Khatoon et al., Advanced Functional Materials, 2025, accepted

Photophysics of Semiconductor Materials and Devices

A very exciting aspect of the field of semiconductors is that the photophysics of materials is at the centre of the subject. The light-matter interactions that lie at the heart of the devices also mean that optical spectroscopy probes fundamental aspects of the device’s operation. We use optical spectroscopy (time-resolved photoluminescence (TRPL) and transient absorption spectroscopy (TAS)) to understand the physics of semiconductor materials and devices especially to investigate the non-radiative losses in light emitting materials and then used innovative strategies to suppress them. We also use these techniques to study exciton/charge diffusion, charge/energy transfer and charge recombination dynamics in nanomaterials, organic and perovskite materials.

Selected Publications 

  1. Siddique et al., J. Mater. Chem. C, 2023, 11, 223-234
  2. G. Nguyen et al., Scientific Reports, 2022, 12, 1-2
  3. Siegmund et al., Advanced Materials, 2017, 29, pp. 1604424.
  4. Park et al., J. Mater. Chem. A, 2016, 4, pp. 827-837.
  5. Allam et al., Physical Review Letters, 2013, 111, 197401

Light Emitting Devices and Sensors

The unique features of organic and hybrid semiconductors such as tunable colours and solution-processability made them attractive materials for displays and lighting applications. This means that inexpensive, large-area, and flexible light sources can be made for many optoelectronic-related products. Our group focuses on developing a transformative fabrication approach to realise high-performance, low-cost, and stable organic and perovskite LEDs.

The early detection of cancer and harmful chemical in water and food will have a huge impact on human life. Our group is using LEDs (along with photodiodes) for skin cancer detection and treatment. Also, we are using them to detect harmfully or concerning analytes efficiently.

 

Selected Publications
  1. Naz et al., Chemistry–An Asian Journal, 2025, 20, e202500136.
  2. G. Nguyen et al., Scientific Reports, 2022, 12, 1-2
  3. Waszkielewicz et al., Nanoscale, 2018, 10, 11335-11341.
  4. Sajjad et al., J. Mater. Chem. C, 2016, 4, 8939-8946.
  5. Bansal et al., Nanoscale, 2015, 7, 11163- 11172.

Visible Light Communication (VLC), Agritech and Photo Dynamic Therapy (PDT)

Our group is actively working with other academic groups and UK industries to use our lab-based optoelectronic devices for real-world problems. For example, we are working with newfocus (EU network) team to develop fast transmitters and receivers for data communication, and with Lambda Energy to develop colour converters for Agritech.

 

Selected Publications
  1. Sajjad et al., Nanomaterials, 2021, 11, 1089
  2. Vithanage et al., J. Mater. Chem. C, 2017, 109, pp. 8916-8920.
  3. Sajjad et al., Applied Physics Letters, 2017, 110, pp. 013302(1-4).
  4. Sajjad et al., ACS Photonics, 2015, 2, 194-199.
  5. Sajjad et., Adv. Opt. Mater., 2015, 3, 536-540