A research group at the HZDR Institute for Ion Beam Physics and Materials Research in Dresden has succeeded in producing encapsulated transistors based on indium selenide and gallium selenide. The encapsulation technique protects the sensitive layers from external influences and preserves their performance. The scientists use hexagonal boron nitride (hBN) for encapsulation. It is ideally suited for this purpose because it can be formed into a thin layer and is inert, i.e. it does not react with the environment
Indium and gallium selenide are considered promising candidates for advanced high-performance applications, for example in high-frequency electronics, optoelectronics or sensor technology. The materials can be used to form flake-like layers with a thickness of only 5 to 10 atomic layers, which in turn enable the production of electronic components with extremely small dimensions. The electrical conduction in these layers takes place only in a 2-dimensional plane.
In the new encapsulation method the two-dimensional flakes are arranged between two platelets of hexagonal boron nitride and thus completely enclosed. The upper hBN layer provides the insulation to the outside, the lower layer serves as a spacer to the carrier material. This technique was originally developed by a research group at Columbia University in New York, where scientist Himani Arora learned it during a research stay. Now, as a doctoral student at the International Helmholtz Research School (IHRS) NanoNet, she is further developing the technique at the HZDR.