Nanostructures will effectively reduce the cost of silicon-based thin-film solar cells by half

According to a recent report by the American Physicists Organization website, Singaporean scientists placed a novel nanostructure (thousands of times smaller than a human hair) on the surface of a non-crystalline silicon solar cell and developed a new thin-film solar cell with high conversion efficiency and low cost. Scientists believe that the latest technology is expected to halve the manufacturing cost of solar cells.

Currently, solar cells are generally made of high-quality silicon crystals, which greatly increases their manufacturing costs and limits their large-scale application around the world. The new thin-film silicon solar cell created by scientists from Nanyang Technological University (NTU) and the Institute of Microelectronics (IME) in Singapore solves this problem.

Scientists first used amorphous (amorphous) silicon films of relatively poor quality and only one percent of the thickness of silicon crystals used in traditional solar cells to create a thin-film silicon solar cell, greatly reducing the manufacturing cost of solar cells.

However, this type of cell is less efficient in converting sunlight into electricity. To this end, scientists have used nanotechnology to create a unique nanostructure on the surface of amorphous silicon solar cells, improving the conversion efficiency of this thin-film silicon cell and increasing energy output. The current generated by the new nanostructured silicon thin-film solar cell is 34.3 mA/cm2, which is comparable to the output current of traditional cells (40 mA/cm2).

"The new nanoscale approach allows this thin-film solar cell to achieve the highest short-circuit current density ever achieved and a conversion efficiency of 5.26%," said Nawa Singh, a senior researcher at the Singapore Institute of Microelectronics and the leader of the research project.

However, the conversion efficiency of general crystalline silicon cells is 20% to 25%. Nawa Singh believes that since the short-circuit current density is directly related to the conversion efficiency, by continuously improving the filling rate and increasing the voltage of the open-circuit current, the conversion efficiency of this silicon thin-film solar cell can eventually be improved to the same level as that of crystalline silicon solar cells. They will then focus on exploring other light-harvesting strategies, such as using surface plasmon photonics technology to capture light.

Zheng Shiqiang, Dean of the School of Electrical and Electronic Engineering at Nanyang Technological University, said that if solar cells are to be "blooming everywhere" around the world, it is very important to improve the conversion efficiency of low-cost solar cells. Nanyang Technological University has been committed to researching cheap, efficient and easy-to-manufacture solar cells so that solar cells can play a greater role and influence in the future renewable energy family.

"Demand for thin-film solar cells is likely to double in 2013," said Kong Dili, director of the Singapore Institute of Microelectronics.