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Cavendish Laboratory, Cambridge

Ibrahim Dar is accepting applications for PhD students.

Postdoctoral Research Associate

We welcome talented and enthusiastic scientists. If you are interested in joining the team, please contact Ibrahim Dar to discuss funding options including Marie-Curie, SNSF, EPSRC, and Newton Fellowships. Please include your CV while doing so.


M. Ibrahim Dar is a Royal Society University Research Fellow in the Cavendish Laboratory at the University of Cambridge. From 2018 to 2020, he was an Advanced Swiss National Science Foundation Post-Doctoral Fellow in the group of Professor Sir Richard Friend, University of Cambridge. Prior to this, he worked as a Post-Doctoral Scientist with Professor Michael Graetzel at Ecole Polytechnique Fédérale de Lausanne (EPFL) Switzerland (2014-2018). For his postdoctoral research at EPFL, he was awarded the prestigious Zeno Karl Schindler-EPFL Prize for particular excellence in the field of sustainability and was twice awarded a special prize by the School of Basic Sciences, EPFL, Switzerland. During his PhD, he was awarded the Swiss Government Excellence Research Scholarships for two consecutive years (2012-2014), which allowed him to work in Professor Graetzel’s group as a guest PhD student. Ibrahim’s interdisciplinary research combines solid-state chemistry, physics, and materials science to design and understand new functional materials with desired structural and optoelectronic properties for energy-oriented applications.


Solid State Chemistry/Physics/Nanoscience for Energy Applications

Ibrahim’s interdisciplinary research in solid-state chemistry, physics, and nanoscience encompasses designing and understanding active materials (light absorbers/emitters) and charge conductors for their applications in devices.

The main research activities span:

  • Developing Perovskite Devices
  • Probing Interfacial Processes in Solar Cells and LEDs
  • Tailoring of Mixed-conduction in Perovskite Semiconductors
  • Nucleation and Crystallization of Solid-state Semiconductors at the Nano-regime


Key publications: 

(*= corresponding author)

 Perovskite Solar Cells

  1. N. Arora,† M. IBRAHIM DAR,†* A. Hinderhofer, N. Pellet, F. Schreiber, S. M. Zakeeruddin, M.  Grätzel* Perovskite solar cells with CuSCN hole extraction layers yield stabilized efficiencies greater than 20%. Science 2017, 358, 768-771. DOI: 10.1126/science.aam5655 (†= authors contributed equally)
  2. Y. Wang, M. IBRAHIM. DAR,* L.K. Ono, T. Zhang, M. Kan, Y. Li, L. Zhang, X. Wang, Y. Yang, X. Gao, Y. Qi,* M. Grätzel,* Y. Zhao* Thermodynamically stabilized β-CsPbI3 based perovskite solar cells with efficiencies >18%, Science, 2019,  365, 591-595. DOI: 10.1126/science.aav8680  
  3. M. Abdi-Jalebi,* M. IBRAHIM DAR, S. P. Senanayak, A. Sadhanala, Z. Andaji-Garmaroudi, L. M. Pazos-Outón, J. M. Richter, A. J. Pearson, H. Sirringhaus, M. Grätzel and R. H. Friend.* Charge extraction via graded doping of hole transport layers gives highly luminescent and stable metal halide perovskite devices. Science Advances, 2019, 5, eaav2012. DOI: 10.1126/sciadv.aav2012
  4. N. Arora,† M. IBRAHIM DAR,†* M. Abdi-Jalebi, F. Giordano, N. Pellet, G. Jacopin, R. H. Friend, S. M. Zakeeruddin, M. Grätzel.* Intrinsic and Extrinsic Stability of Formamidinium Lead Bromide Perovskite Solar Cells Yielding High Photovoltage. Nano Letters 2016, 16, 7155–7162. DOI: 10.1021/acs.nanolett.6b03455  (†= authors contributed equally)
  5. M. IBRAHIM DAR,* M. Abdi-Jalebi, N. Arora, T. Moehl, M. Grätzel, and M. K. Nazeeruddin.*  Understanding the impact of bromide on the photovoltaic performance of CH3NH3PbI3 solar cells. Advanced Materials 2015, 27, 7221–7228. DOI:10.1002/adma.201503124


Emission Spectroscopy

  1. M. IBRAHIM DAR,* G. Jacopin, S. Meloni, A. Mattoni, N. Arora, A. Boziki, S. M. Zakeeruddin, U. Rothlisberger, M. Graetzel. Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites. Science Advances 2016, 2, e1601156. DOI: 10.1126/sciadv.1601156
  2. D. Bi, W. Tress, M. IBRAHIM. DAR, P. Gao, J. Luo, C. Renevier, K. Schenk, A. Abate, F. Giordano, J.-P. Correa Baena, J.-D. Decoppet, S. M. Zakeeruddin, M. K. Nazeeruddin, M. Grätzel, A. Hagfeldt. Efficient luminescent solar cells based on tailored mixed-cation perovskites. Science Advances 2016, 2, e1501170. DOI:  10.1126/sciadv.1501170
  3. N. Arora,† M. IBRAHIM DAR,†* M. Hezam, W. Tress, G. Jacopin, T. Moehl, P. Gao, A. S. Aldwayyan, B. Deveaud, M. Grätzel, and M. K. Nazeeruddin. Photovoltaic and Amplified Spontaneous Emission Studies of High-Quality Formamidinium Lead Bromide Perovskite Films. Advanced Functional Materials 2016, 26, 2846–2854. DOI: 10.1002/adfm.201504977  (†= authors contributed equally
  4. M. IBRAHIM DAR,* G. Jacopin, M. Hezam, N. Arora, S. M.Zakeeruddin, B. Deveaud, M. K. Nazeeruddin, M. Graetzel. Asymmetric cathodoluminescence emission in CH3NH3PbI3-xBrx Perovskite Single Crystals. ACS Photonics 2016, 3, 947–952. DOI: 10.1021/acsphotonics.6b00290  


Growth and Crystallization 

  1. Y. Liu, S.Akin, L. Pan, R. Uchida, N. Arora, J. V.  Milic, A. Hinderhofer, F. Schreiber, A. R. Uhl, S. M. Zakeeruddin, A. Hagfeldt, M. IBRAHIM DAR,* M. Grätzel* Ultra-Hydrophobic 3D/2D Fluoroarene Bilayer-Based Water-Resistant Perovskite Solar Cells with Efficiencies Exceeding 22%. Science Advances, 2019, 5, eaaw2543 DOI: 10.1126/sciadv.aaw2543
  2. M. IBRAHIM. DAR*, A. Hinderhofer, G. Jacopin, V. Belova, N. Arora, S. M. Zakeeruddin, F. Schreiber and M. Grätzel. Function Follows Form: Correlation between the Growth and Local Emission of Perovskite Structures and the Performance of Solar Cells. Advanced Functional Materials, 2017, 27, 1701433. DOI: 10.1002/adfm.201701433
  3. A. Greco, A. Hinderhofer,* M. IBRAHIM. DAR,* N. Arora, J. Hagenlocher, A. Chumakov, M. Grätzel and F. Schreiber. Kinetics of Ion-Exchange Reactions in Hybrid Organic–Inorganic Perovskite Thin Films Studied by in Situ Real-Time X-ray Scattering. The Journal of Physical Chemistry Letters, 2018, 9, 6750-6754. DOI: 10.1021/acs.jpclett.8b02916  


Atomic and Molecular Modulation

  1. X. Li, M. IBRAHIM DAR, C. Yi, J. Luo, M. Tschumi, S. M. Zakeeruddin, M. K. Nazeeruddin, H. Han, M. Grätzel* Improved performance and stability of perovskite solar cells by crystal crosslinking with alkylphosphonic acid ω-ammonium chlorides. Nature Chemistry 2015, 7, 703-711. DOI: 10.1038/nchem.2324
  2. M. IBRAHIM DAR,* N. Arora, P. Gao, S. Ahmad, M. Grätzel,* and M. K. Nazeeruddin.* Investigation Regarding the Role of Chloride in Organic-Inorganic Halide Perovskites Obtained from Chloride Containing Precursors. Nano Letters 2014, 14, 6991–6996.  DOI: 10.1021/nl503279x
  3. M. IBRAHIM DAR, F. J. Ramos, Srinivasrao A. Shivashankar, Shahzada Ahmad, Bin Liu, Mohammad Khaja Nazeeruddin,* and Michael Grätzel.* Photoanode based on (001)-oriented anatase nanoplatelets for organic-inorganic lead iodide perovskite solar cell. Chemistry of Materials 2014, 26, 4675–4678. DOI: 10.1021/cm502185s





Teaching and Supervisions




  • NE.10: Energy Harvesting (Lent Term)

Dr M. Ibrahim Dar

Energy, which has been playing a critical role in shaping human activities and demands, can be unambiguously considered a "modern currency". To meet the current demands of our society, we need to revolutionize technologies targeting the harnessing of green and abundant energy available on earth while improving high-energy-density electrochemical energy storage devices. Materials science, which holds a central position in energy-oriented research domains, continues designing and investigating diverse materials to capture different forms of energy ranging from solar to thermal and mechanical energy. In this module, we discuss the significance of miniaturization in energy harnessing devices by referring to various nanomaterials-based energy conversion technologies involving photovoltaics, thermoelectricity, piezoelectricity and pyroelectricity. After thoroughly discussing energy harnessing devices, we extend our focus to energy storage systems.


Typically, this module covers

  • The role of nanomaterials in energy harnessing,
  • Fundamental understanding of next-generation solar cells,
  • Nanostructured thermoelectric, piezoelectric, and pyroelectric materials and devices, and
  • Promising nanomaterials for high-energy-density batteries and supercapacitors


  • NE.05: Nanomaterials (Lent Term) Core

Dr M. Ibrahim Dar, Prof. Stephan Hofmann, Dr Jack Alexander-Webber

The remarkable properties of nanomaterials have attracted immense interest in both pure and applied science. Applications span many areas of significance to society, such as catalysis, bio-sensing and energy harvesting. To utilise the unique properties of nanomaterials, a thorough understanding of their unique materials science is required.

The compositional and structural control at the nanometre scale can lead to unprecedented chemical and physical effects while dramatically enhancing some properties. The materials of interest for such effects of length scale are wide-ranging, including metals, semiconductors, ceramics, polymers, and composites. The examples of metal, semiconductors and carbon (from fullerenes to carbon nanotubes and graphene) nanomaterials will be discussed in detail to show how the “bottom-up” synthetic approaches can give rise to materials of low dimensionality (0D, 1D and 2D) exhibiting unique properties, desired for various applications. Examples of the growth and applications of 2D nanomaterials will also be covered.

This lecture series will provide the salient grounding and broad skills necessary to understand inorganic nanomaterials in a contemporary nanoscience context. Detailed coverage will be given of selected special interest topics. The course will also touch upon the topic of nanomanufacturing, emphasizing the transition to technology and need for scalable processes.

Research supervision: 

Ibrahim is accepting applications for PhD students. We also welcome talented and enthusiastic scientists.

Royal Society University Research Fellow

Contact Details

Email address: 
Optoelectronics Group (K33)
Cavendish Laboratory
University of Cambridge
J J Thomson Avenue
+44 1223337390