Vietnamese PhD develops solar cell technology
Dr. Nguyen Trong Hieu's team at the Australian National University recently announced the breakthrough discovery they believe could revolutionize solar technology.
Dr. Hieu shared, the key factor to increase the efficiency of conversion solar energy into battery power is to improve the quality of materials, enabling to link those materials together and therefore absorb more sun energy. The team improved perovskite material (naturally occurring mineral of calcium titanate) by coating a thin and transparent layer of PMMA-PCBM polymer film. In solar cells, perovskite is used to replace silicon, making it cheaper, easily handling in terms of technology, but low efficiency of power conversion. For example, the same size of the material is one square meter, the efficiency of perovskite material is less than 20% while silicon is above 26%.
This polymer film helps to fill the boundaries between the crystals in perovskite, because between them are many defect regions that cause charged particles moving into this region disappeared and no electricity obtained. Despite durability, polymer has a poor conductivity, so in order to improve this feature, Dr. Hieu et al. fabricated carbon nanotubes, which are placed through the polymer membrane for charged particles can easily pass through. As a result, the conversion efficiency of the battery reaches 21.6%. "Perovskite battery area (larger than 1cm2) reaches efficiency of over 20%, only several research groups in the world can achieve," he said.
An increase of 1% efficiency seems small but it leads to another value chain such as materials, transportation or minimal land/roof area required for battery installation," he added. Assuming that if the average efficiency of silicon panels on the current market increases from 20% to 21%, then the industry will save more than $ 2 billion annually globally.
According to Dr. Nguyen Trong Hieu, a special part of this research is that the research team has taken common materials and tools available in the market and turned them into extraordinary.
The research team has tested the invention on a variety of modern perovskite solar cells manufactured at the Australian National University (ANU), and the test results were independently verified with a variety of technicians with other low resolution or speed. The team is refining the invention for commercialization.
Dr. Nguyen Trong Hieu was born in 1988, went to Australia to study in early 2013 with ANU's full doctoral scholarship on research on semiconductor materials for solar cells. In 2017, he was a visiting scientist at the United States' National Renewable Energy Laboratory. Currently, Dr Hieu is a senior research fellow and senior lecturer in the field of solar power technology at the ANU.