Prof. Mohammad K. Nazeeruddin

A Solar Mind’s Odyssey  

A Journey that Wove Science from the Soil of India to the Sky of New Energies 
In India, where medicine and engineering are the shared dreams of many children, a young boy in Hyderabad’s elementary classrooms quietly charted a different path in his mind. He saw that while medicine was noble, its impact was often confined to a small sphere. This yearning for greater growth and progress shifted his choice, turning chemistry into the new course of his life—a decision that might have seemed minor to others but laid the foundation for a distinct future. This is the story of Mohammad Khaja Nazeeruddin: a tale of successive choices, each of which opens a new chapter in his life.
The First Life Equations 
Mohammed Khaja Nazeeruddin was born in 1957 in India and spent his childhood in Tumkur. At the tender age of five, he lost his father, plunging his family into new hardships. During this time, his brother took on the responsibility of supporting him, while his teacher’s affection and encouragement kept him motivated in his studies. Nazeeruddin’s scientific journey began at Osmania University in Hyderabad, where he chose a combination of chemistry and biology for his undergraduate studies. While studying the basic sciences meant understanding the foundations of the universe, it was primarily the start of a journey that later led to the development of solar cell technology. After graduating, Nazeeruddin took the entrance exam for advanced studies and, among numerous candidates, secured admission to programs in both genetics and chemistry. Although he was drawn to genetics, the field was not widely recognized in India at the time, so he pursued chemistry instead. After completing his bachelor’s degree in 1978 and master’s degree in 1980, his focus shifted to inorganic chemistry—a discipline concerned with the properties and reactions of all elements and non-hydrocarbon compounds. In 1986, under the guidance of his mentor, Dr. Taqi Khan, he completed his Ph.D. at Osmania University, a milestone that formally launched him into the research field. During those same years, Nazeeruddin also worked as a research associate at the Central Salt and Marine Chemicals Research Institute in Bhavnagar, where he took his first professional steps in applied research.
Pivotal Choices
In 1985, Nazeeruddin became a lecturer Osmania University’s Deccan College of Engineering and Technology. However, he soon realized that staying in that role would not satisfy his desire for progress. Dr. Taqi Khan encouraged him to pursue, he pursued a scholarship opportunity. His primary concern was finding ways to produce ammonia at lower costs and temperatures—a matter of great importance for Indian agriculture. With this idea, he attended an interview in Delhi, secured a scholarship, and sent applications to universities worldwide. Three distinguished professors—Bill Gibson from Imperial College London, Cotton from the University of Texas in the USA, and Michael Grätzel from EPFL in Switzerland—expressed an interest in collaborating with him. Ultimately, Nazeeruddin chose Grätzel, believing that his younger age would translate into bolder ideas and a better growth environment. Thus, he joined EPFL for his postdoctoral research. In Michael Grätzel’s group, which focused on renewable energy and catalysis, Nazeeruddin’s interests shifted toward renewable energy. He began his career as a postdoctoral researcher and has continueded in various roles over the years. From 2009, he served as a full professor at the School of Advanced Materials Chemistry at Korea University for 5 from 2012 to 2022, he was a full professor in the Molecular Engineering of Functional Materials group at EPFL. These years paved the way for his focus on a technology that now defines his work: perovskite solar cells. His emphasis on perovskite, an emerging material in solar cells, has contributed to a global shift in the perception of solar energy. Since the early 20th century, this crystalline material has garnered significant attention in recent years due to its exceptional properties in converting solar energy. Perovskite solar cells represent a new generation of clean energy technologies, that offer high efficiency, low production costs, and ease of manufacturing. The focus of Mohammad Nazeeruddin on this technology is a vital part of efforts to advance renewable energy sources.
A Footprint of Global Statistics and Recognition
Mohammad Nazeeruddin has published over 980 peer-reviewed articles in prestigious journals, authored 10 book chapters, and holds 1a total of 103 patents. His three primary patents include the N3 and N790 dyes, a two-step deposition method for manufacturing perovskite solar cells, and the use of a special coating to prevent lead leakage in these cells—innovations that have significantly advanced solar energy technologies. His research has been cited more than 194,000 times, with an h-index of 197, placing him among the world’s most-cited scientists. From 2014 to 2024, Nazeeruddin consistently appeared on the ISI Highly Cited Researchers list and has been invited to speak at over 450 international conferences. His collaborations extend beyond academia, encompassing major industrial partners such as Panasonic, NEC, TOYOTA-AISIN, TOYOTA-Europe Motors, Solaronix, and ABENGOA, with some of his research funded by these entities. His contributions earned him a place among Thomson Reuters’ 19 Most Influential Scientific Minds in 2015. Additionally, Nazeeruddin is a member of the European Chemical Society, the European Academy of Sciences, the Royal Society of Chemistry in the UK, and the Telangana Academy of Sciences, reflecting the breadth of his international scientific engagement. He has also served on the editorial and review boards of several prestigious scientific journals, roles that underscore his significant influence in critiquing, evaluating, and guiding research trends in his specialized fields.
A Testament to Dedication
Throughout his professional career, Mohammad Nazeeruddin has received an array of scientific accolades, receiving at least 20 national and international awards, each affirming his contributions to the advancement of renewable energy knowledge, the development of metal complexes, and particularly perovskite solar cells. He attributes these honors to his efforts in engineering perovskite compositions, optimizing interfaces, and improving charge transport layers—innovations that have achieved record efficiencies in this technology and offered a fresh perspective on the future of clean energy. Among these accolades, some stand out prominently. In 2021, Nazeeruddin received the prestigious Khwarizmi International Award in Fundamental Sciences. In 2025, he was awarded the Mustafa Prize. He has also received numerous fellowships and awards in countries such as India, Japan, Brazil, and Switzerland. Each of these recognition paints a picture of his impact on a field addressing one of humanity’s most critical challenges: developing sustainable energy for a greener future.
The journey of Mohammad Nazeeruddin’s encapsulates a series of choices and experiences. At various stages of his life, he made decisions among different disciplines and mentors, each of which opened a new path. From his early days at Osmania University where he weighed genetics against chemistry, to his decision to move to Switzerland to work with Michael Grätzel, and to his later focus on renewable energy and perovskite solar cells, every step of his career woven a new thread. Beyond numbers and accolades, his life exemplifies the fusion of science with practical applications. His story illustrates that research is not about reaching an endpoint but an ongoing journey—one that continues to unfold, with new chapters yet to be written.
 

Perovskite Solar Cells Revolution  

The Dream of Limitless Electricity
We have all experienced power outages countless times—moments when cooling devices stop working, lights go out, and silence and darkness take over. These situations deprive us of even the most basic daily needs. Such experiences remind us of our deep dependence on electricity and the critical importance of access to energy. This reliance persists while a significant portion of electricity is still generated by burning fossil fuels—resources that are not only finite and depleting but also cause widespread environmental harm through greenhouse gas emissions, air pollution, and the exacerbation of the climate crisis. These crises threaten human health and the future of our planet. In response to these challenges, renewable energy sources, particularly solar energy, have emerged as sustainable and clean alternatives. Solar energy is one of the cleanest and most accessible options has drawn attention for years. However, conventional technologies for harnessing it have faced issues such as high costs, complex production processes, and limited efficiency. In this context, perovskite solar cells have emerged as a new generation of solar technology, rekindling hope. These cells, with their lower costs and higher efficiency, have challenged the limitations of previous technologies and captured widespread attention. In this field, researchers like Mohammad Nazeeruddin have played a key role in advancing this emerging technology, paving the way for clean, sustainable, and accessible energy for all.
The Old Brick of the Solar Cell Building
When we talk about solar panels, we’re actually referring to small units called solar cells—tiny components arranged together to capture sunlight and convert it into electricity. In the first generation of this technology, these cells were made from a material called silicon. In this structure, a solar cell consists of two types of silicon with distinct properties. The first type, known as n-type, is doped with phosphorus, which gives it extra electrons. The second type, called p-type, is doped with elements like boron, resulting in a shortage of electrons. In p-type silicon, this electron deficiency creates empty spaces called holes that are eager to be filled. When these two types of silicon are placed side by side, electrons move from the n-type to the p-type at their boundary, filling these holes. Once this electron transfer is complete, the resulting charge difference between the two silicon types creates a special region known as the depletion zone. This zone, influenced by an internal electric field, acts as a barrier, preventing the free movement of additional electrons. At this point, electrons can no longer easily pass through this short path between the n-type and p-type. This field acts like a gatekeeper, preventing the recombination of electrons and holes and creating a new pathway for electron flow. From then on, if the energy from light particles (photons) dislodges an electron from a silicon molecule, it helps push the electron and hole in opposite directions, generating an electric current. The freed electrons move toward an external circuit, travel through it, and return to the cell, where they recombine with holes. This continuous movement is the electric current derived from sunlight.
The Hero Called Perovskite
Silicon solar cells have been the foundation of solar panels for years. Despite their many successes, they still face limitations such as low efficiency, high costs, complex manufacturing processes, and reliance on rare materials. These challenges paved the way for new technologies, leading to the emergence of a new generation of solar cells known as perovskite solar cells. The term "perovskite" originally refers to a specific crystal structure with the general formula ABX₃. In this structure, A is typically an organic cation like methylammonium, B is a metal such as lead, and X is a halogen like iodine. While the basic operation of these cells is similar to that of silicon cells, their constituent materials, thanks to their well-organized crystal structure and chemical flexibility, can efficiently absorb light and transfer electrical charges.
Under the Umbrella of Additives
As promising as perovskites are, their structural stability diminishes when exposed to moisture and heat. This characteristic poses a major obstacle to their widespread commercialization, and this is where Mohammad Nazeeruddin’s efforts stand out. To address this challenge, various approaches have been explored. One such approach involves combining two-dimensional (2D) and three-dimensional (3D) structures, which not only enhances resistance to moisture penetration but also improves long-term performance stability. In perovskite solar cells, the crystal lattice extends in three dimensions, forming a 3D structure. In the mentioned method, by adding fluorinated groups such as fluoro-phenyl ethylamine and pentafluoro-benzylamine to the surface layer, this layer is transformed into a 2D structure. The resulting structure is hydrophobic, acting like a shield to prevent degradation of the cell’s core components. In another study, compounds like alkylphosphonic acid ω-ammonium chloride were introduced, serving as molecular bridges that connect the edges of perovskite crystals, creating a more cohesive and robust structure. This surface modification enabled the cells to retain over 80% of their initial efficiency even after a week of exposure to 55% humidity, while uncoated samples rapidly lost their performance. Additionally, research demonstrated that simultaneously adding a dopant like methylammonium chloride (to tune electrical properties) and an additive like 1,3-bis(cyanomethyl)imidazolium chloride (to enhance crystalline and chemical quality) resulted in the formation of a uniform and stable perovskite layer. This synergy played a significant role in reducing defects and boosting performance. Furthermore, the use of phosphonic acid additives improved the cohesion and order of the perovskite crystal structure. Such optimizations not only increased efficiency from around 9% to over 16% but also significantly enhanced the cells’ performance stability under high relative humidity conditions.
Electrons in Energy Traps
To improve the efficiency and stability of perovskite solar cells, a deeper understanding of electron behavior and the energy levels of the layers became essential. As previously mentioned, a solar cell consists of multiple layers, each playing a distinct role in converting sunlight into electricity. The most critical of these is the active layer, where light is absorbed, and electrons are dislodged from their atoms to generate an electric current. Each material in this structure has specific energy levels for its electrons. If the energy levels between layers, such as the absorber layer and the charge transport layers, are not properly aligned, electrons lose energy or become trapped during transfer. One cause of this trapping is the presence of energy traps—points in the material’s structure where, due to defects or crystal mismatches, electrons are captured, preventing their movement through the circuit. This phenomenon leads to reduced current, energy loss, and ultimately lower efficiency. To tackle this issue, various strategies were proposed. One approach involved introducing non-thermal plasmas into the perovskite structure, which deactivated energy traps caused by crystal defects and optimized energy level alignment. Additionally, efforts were made to optimize the chemical composition of the active layer. For instance, Mohammad Nazeeruddin’s team successfully formed more uniform and ordered crystals by adding a controlled amount of excess lead iodide (PbI₂) to the perovskite layer. These crystals had fewer traps and delivered higher efficiency. The result of these modifications was the development of cells with efficiencies exceeding 20%, which retained a significant portion of their performance even after exposure to real-world environmental conditions. Such advancements underscore that achieving an ideal composition requires a deeper understanding and precise engineering of the behavior of electrical charges.
Uniform Crystals with a Green Concern
In the ongoing efforts to optimize fabrication processes, has focused on improving the methods for producing perovskite solar cells. One of the challenges in manufacturing these cells was creating a uniform, high-quality layer of the light-absorbing material—a problem that manifested in early methods like one-step deposition due to irregular crystal growth. Mohammad and his colleagues advanced this field by introducing a novel approach called sequential deposition. This two-step process begins with the formation of a lead iodide layer, which is then exposed to an organic halide solution to transform into perovskite. This method allows better control over crystal growth, enhancing the uniformity and efficiency of the cells. Cells produced using this technique retained up to 80% of their performance even after 500 hours of operation. However, advancements in performance are only part of the story. Environmental sustainability has also become a significant concern in the development of perovskite solar cells. One of the most challenging issues is the use of lead in their structure—a heavy and toxic metal that, despite its critical role in boosting efficiency, raises serious environmental safety concerns. To address this, researchers have explored low-lead or lead-free structures, with some proposing the use of tin as a substitute for lead. Although these alternatives are not yet as efficient as lead-based compositions, they represent a crucial step toward combining high performance with environmental responsibility. Nazeeruddin’s team ultimately succeeded in preventing lead leakage from these cells by using a specialized coating.
Broadly speaking, perovskite solar cells represent a social innovation that enables the provision of affordable and reliable electricity in underserved regions, reduces global reliance on fossil fuels, and promotes energy equity. These achievements, built over 12 years, have paved the way for the development of a new generation of solar cells with practical and commercial potential, facilitating the realization of sustainable and accessible energy systems. As Nazeeruddin states: “We have come a long way. We’ve gone from efficiencies below 10% to 26%, a figure that has been officially verified and published in research papers. This is a tremendous achievement. In terms of stability, we’ve also made significant progress, and now we can say these cells are stable and ready for market entry. However, it will take a few more years to achieve widespread adoption. When that happens, most developing and underdeveloped countries will be able to adopt them easily, as they are considered a low-tech product from a technological perspective.”