A JOURNEY IN THE FIELD OF SOLAR CELLS – FROM SILICON TO PEROVSKITE
Keywords: renewable energy, material science, photovoltaics, biofuel, climate action, perovskite, future of solar
Dorota Bacal is a 3rd year PhD candidate in Chemical Engineering at Monash. She realised the urgency, complexity, and impact of adopting a low carbon emission economy at COP24. Her presence at the COP24 reinforced her belief that a synergy of renewable energy sources is required to meet global electricity demand. “Solar is one of the major energies that can be found everywhere in the world, with no need for rivers or a constant wind to provide power. It’s easily up- and down- scalable - you can have it on one roof or have a field of solar panels - and does not require a huge upfront investment. This makes it extremely attractive for remote areas with no electricity grid. Everyone, from young members of NGOs to big political and government associations, came to COP24 to contribute to the positive change. I was proud to be part of the Monash delegation. Monash University is like a small city, striving towards net zero emissions and leading the way for others with scalable, transferrable technologies”.
Dorota’s research focuses on perovskites at the Advanced Photovoltaic Lab, where device fabrication techniques and optimisation work are undertaken to maximise efficiency. Dorota masters the use of fabrication techniques including photolithography, e-beam evaporation, and atomic layer deposition, and characterisation including SEM, PESA, and photoluminescence mapping. Easily-manufactured, low-cost, efficient perovskite cellscould revolutionise the solar energy industry. Dorota and colleagues also work on increasing perovskite cells lifetime and durability. “We measure solar cells during the exposure to some gases; how fast and what concentration affects the perovskite layer positively or negatively. Water vapour causes the degradation of perovskite material - hence, we encapsulate it to avoid the problem - however Pyridine causes an increase of the efficiency due to the passivation of the surface of the material”.
Perovskite cells could be incorporated into a much greater proportion of the built environment than existing cells. “Perovskite materials are available in many different colours and can be deposited from a solution. They can be 2D printed on flexible substrates. There is still long way to go to fully commercialise this new technology – this is where I come to play. The Udo Bach research group is the only lab in the world that successfully produced back-contact perovskite solar cells, with both positive and negative electrodes at the back of the device, allowing real time measurement of the perovskite layer during the manufacturing process. I am varying the annealing time of perovskite materials and can measure and optimise cell performance while it is still on the hot plate. This is impossible in the standard planar structure, because they don’t yet have two electrodes. This gives us an advantage of much faster optimisation of deposition techniques.
Dorota’s interest in renewable energy sources also targets biofuel. Electricity consumption is the largest industrial greenhouse gas emitter, but transport also plays a major role. “It is very easy to imagine family-size electric cars replacing ones running on fossil fuels. However, with bigger vehicles, like long-distance trucks, ships and planes, where the battery capacity is not enough, another type of renewable energy is needed. During one of the Centre of Excellence in Exciton Science workshops, I was introduced to Rebecca Yee, Director of Biofuel Innovations, an Australian company with a long history in biofuel. They built a proof of concept plant manufacturing biofuel from waste cooking oil in Dandenong. Together with Biofuel innovations, I’m looking at developing a sustainable business model of algae biofuel production. We are also looking at carbon – capturing technologies to help achieving the net zero emission target.
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