The National Key Laboratory of solid lubrication, Shirki academician and Zhang Guangan researcher, Chinese Academy of Sciences, Lanzhou Institute of Chemical Physics, supported by the National Natural Science Foundation of China and the leading scientific research project of the Chinese Academy of Sciences, has made new progress in theoretical research on the electrical properties of six square boron nitride.
As a kind of wide band gap Insulator, six square boron nitride has hindered its wide application in electronic devices, and the research of its band structure engineering can develop many potential application values. For example, the transformation of the belt structure: the transition between the direct band gap and the indirect band gap is very important for its application in the Light-emitting nano-devices and ultraviolet laser devices. All of these will inspire the researchers to control the band gap through various feasible means, so far the methods of controlling six square boron nitride bandgap are mainly applied electric field, doping, deformation and so on. Although these methods are helpful in regulating the bandgap of six square boron nitride, the nature of band gap transition is still unclear, and the relationship between crystal structure change and band gap transition and its electronic performance still needs further study.
We use the pressure to control six square boron nitride bandgap, which is a simple and feasible method compared with the above methods, and does not introduce foreign impurities. Coupled with the change of the electronic properties of six square boron nitride under normal pressure has not been reported systematically, many interesting phenomena still need to be explored, and in-depth understanding of the relationship between the electronic properties and pressures of six square boron nitride is very important for its applications in electronic devices. To this end, we further studied the changes of the electronic properties of six square boron nitride under normal pressure in three different heap arrangement modes, the adsorption energy and band gap of six square boron nitride under pressure were calculated by the method of first-order principle, and the variation trend of band gap with pressure was analyzed by the energy band structure and the electronic local functional function. The results show that the normal pressure can well regulate the bandgap of six square boron nitride, under the Shan and Shan of the heap arrangement mode, the band gap decreases with the increase of pressure first and then decreases, which is very different from the trend of monotonic reduction of the band gap under the electric field regulation, and the Shan of the stacking arrangement mode decreases monotonically with the increase of pressure. When the pressure reaches 34.3% (heap arrangement mode Shan), the six square boron nitride is changed from the direct band gap to the indirect band gap, which is very important for the application of the six square boron nitride in the light-emitting device. The pressure reaches 28.6% (heap arrangement mode Shan) and 45.7% (heap Arrangement Mode III) transition from insulator to semiconductor, which is very important for the wide application of six square boron nitride in electronic devices. The results were published in the recently published Ceramics International (2017, 43, 6626).