The electric properties and the current-controlled differential negative resistance of cBN crystal

The electric properties of nonintentionally doped n-cubic boron nitride (cBN) crystal are investigated. The cBN crystal was transformed from hexagonal-boron nitride (h-BN) under high pressure (HP) and high temperature (HT) using magnesium powder as catalyst. At room temperature, the current-voltage (I-V) characteristics of cBN crystal are measured and found to be nonlinear. When the electric field is in the range of (1−1.5) × 10⁵ V/cm, the avalanche breakdown occurs inside the whole cBN crystal. At this same time, the bright blue-violet with the wavelength of 380–400 nm from the cBN crystal is observed. When measuring the I–V curve after breakdown of cBN crystal, the current-controlled differential negative resistance phenomenon is observed. The breakdown is repeatable. Supported by the Research Foundation of Zhuhai College of Jinan University for recruited excellent talents (Grant No. 510062)