The properties are soft, the thickness is only a few nanometers, and the optical properties are good… The reporter learned from Nanjing University of Technology on the 3rd that Professor Wang Lin’s research team prepared an ultra-thin high-quality two-dimensional lead iodide crystal, and realized the control of the optical properties of two-dimensional transition metal sulfide materials through it, providing a new idea for the manufacture of solar cells and photodetectors. This achievement was published in the latest international journal Advanced Materials.
“The ultra-thin lead iodide nano-sheet we prepared for the first time is called ‘wide bandgap two-dimensional PbI2 crystal with atomic thickness’ in the professional terminology. It is an ultra-thin semiconductor material with a thickness of only a few nanometers.” Sun Yan, the first author of the paper and doctoral candidate of Nanjing University of Technology, said that they used the solution method to synthesize it, which has low requirements for equipment, and has the advantages of simple, fast and efficient, It can meet the material preparation requirements of large area and high output. The synthesized lead iodide nanoflakes have regular triangular or hexagonal shape, average size of 6 microns, smooth surface and good optical properties.
The researchers combined this ultra-thin lead iodide nano-sheet with two-dimensional transition metal sulfides, and carried out artificial design. They stacked them together to obtain different types of heterojunction. Because of the different arrangement of energy levels, lead iodide 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 conducive to the production of devices such as light-emitting diodes and lasers, which can be used in display and lighting, and can also be used in photoelectric detectors, photovoltaic devices and other fields.
This achievement has realized the control of ultra-thin lead iodide on the optical properties of two-dimensional transition metal sulfide materials. Compared with the traditional optoelectronic devices based on silicon-based materials, this achievement has the characteristics of flexibility and micro-nano, so it can be applied to the preparation of flexible and integrated optoelectronic devices. The two-dimensional semiconductor heterostructure based on lead iodide nano-slice has broad application prospects in the field of integrated micro-nano optoelectronic devices, It also provides a new idea for manufacturing solar cells, photodetectors, etc.