High (p,T) properties of wide band-gap semiconductors from second harmonic generation measurements

我们建议测量宽禁带半导体氧化锌和氮化铝在高压和高温(高达50 Gpa和3500 K)下的相界和熔化曲线。这些测量是获得改善掺杂化合物合成的数据所必需的，而掺杂化合物的合成又是优化器件性能所必需的。我们将通过测量光学二次谐波产生信号的强度和发射辐射的变化来确定熔化的开始和相界的斜率。这些测量将允许使用经验势来测试基于分子动力学模拟的预测。以氮气为压力介质的激光加热实验将为我们深入了解在氧化锌和氮化铝的高压相中掺杂的可能性。用一种基于Maker条纹测量的新方法研究了高压对折射率和二次谐波的影响。

We propose to measure the phase boundaries and the melting curves of the wide band-gap semiconductors ZnO and AlN at high pressures and high temperatures (up to 50 GPa and 3500 K). These measurements are necessary to obtain data to improve the synthesis of doped compounds, which in turn are needed to optimise device performances. We will determine the onset of melting and the slope of the phase boundaries by measuring the intensity of the optical second harmonic generation signal and from the change in the emitted radiation. These measurements will allow to test predictions based on molecular dynamics simulations using empirical potentials. Laser heating experiments with nitrogen as the pressure medium will provide insight into the possibility of doping in the high pressure phase of ZnO and AlN. The e_ect of high pressure on the refractive indices and on the second harmonic generation will be studied using a new approach based on Maker fringe measurements.