Researchers at North Carolina State University just made a nano shish kebab out of germanium sulfide (GeS) crystals – but it’s not for the world’s smallest barbecue. Instead, the first-of-its-kind nano-structure could lead to the development of 3-D solar cells and next-generation sensors, supercapacitors, and photodetectors.
To create the nano-shish-kebabs, researchers first made a GeS nanowire about 100 nanometers in width. Then they exposed it to air, which causes nucleation sites to form on the wire surface due to weak oxidation. After that, they exposed the wire to GeS vapor, resulting in the formation of two-dimensional nanosheets at each of the nucleation sites. This is the first engineered nano-material made of one-dimensional and two-dimensional forms with a shared crystalline structure.
According to the research report, “Combining the nanowire and nanosheets into a single ‘heterostructure’ creates a material with both a large surface area and — because GeS is a semiconductor — the ability to transfer electric charges efficiently. The nanosheets provide a very large surface area, and the nanowire acts as a channel that can transmit charges between the nanosheets or from the nanosheets to another surface.”
This same type of heterostructure could be constructed by using other materials whose molecules have the same kind of crystalline layers, such as molybdenum sulfide (MoS2). MoS2 could perform better than GeS in electronic applications, especially in photovoltaic cells, which makes this new discovery very promising in the quest to increase solar cell efficiency.
Via Clean Technica
Images via North Carolina State University