NTU prepared thin and soft new semiconductor materials

The soft nature, the thickness is only a few nanometers, and the optical performance is good ... The reporter learned from Nanjing University of Technology on the 3rd that the group of professor Wang Lin of the school prepared an ultra-thin high-quality two-dimensional lead iodide crystal, and achieved it through it. The regulation of the optical properties of two-dimensional transition metal sulfide materials provides new ideas for the manufacture of solar cells and photodetectors. The result was published in the latest issue of the International Journal "Advanced Materials".

"The ultra-thin lead iodide nanosheets we prepared for the first time, which is termed 'atomic thickness wide band gap two-dimensional PbI2 crystal', is an ultra-thin semiconductor material with a thickness of only a few nanometers." The first author, Sun Yan, a doctoral student at Nanjing University of Technology, said that they used the solution method to synthesize. This method requires low equipment, has the advantages of simplicity, speed, and efficiency, and can meet the needs of large-area and high-volume material preparation. . The synthesized lead iodide nanosheets have regular triangular or hexagonal shapes, with an average size of 6 microns, a smooth and smooth surface, and good optical properties.

Researchers combined this ultra-thin lead iodide nanosheet with two-dimensional transition metal sulfide, artificially designed them, and stacked them together to obtain different types of heterojunctions. Because the energy levels are arranged differently, the iodine Lead can have different effects on the optical performance of different two-dimensional transition metal sulfides. This energy band structure can effectively improve the luminous efficiency, and is beneficial to the manufacture of devices such as light-emitting diodes and lasers. It is used in display and lighting, and can be used in photodetectors, photovoltaic devices and other fields.

This achievement has achieved the control of the optical properties of two-dimensional transition metal sulfide materials by ultra-thin lead iodide. Compared with the traditional optoelectronic devices with silicon-based materials as the main body, this achievement is flexible and micro-nano, so it can be used in For the preparation of flexible and integrated optoelectronic devices, the two-dimensional semiconductor heterojunction based on lead iodide nanosheets has broad application prospects in the field of integrated micro-nano optoelectronic devices. It is used to manufacture solar cells, photodetectors, etc. Wait, also provided a new idea. (Reporter Zhang Ye correspondent Zhou Wei)