高性能垂直型GaN-on-GaN二极管的研究

由于高质量自支撑氮化镓(GaN)衬底的出现,垂直型GaN-on-GaN器件获得了快速的发展并具有较高的功率等级和工作频率.本文讨论了垂直型GaN功率二极管的制作、机制和表征.通过制作高质量肖特基界面和高效氟离子注入终端,垂直型GaN肖特基二极管可以表现出较低的正向开启电压(0.55 V,定义于0.1 A/cm2)和较高的反向击穿电压(～800 V).通过极薄的铝镓氮(AlGaN)隧穿增强层,可进一步同时优化正向开启电压(0.43 V)和反向击穿电压(～1020 V).在快速动态测试电路中,垂直型GaN二极管也表现出了接近零的反向恢复特性和无电流坍塌的优异动态特性.     

Cavity enhanced absorption spectroscopy for N_2O detection at 2.86 μm using a continuous tunable color center laser

The cavity enhanced absorption technique is applied to N2O detection around 2.86 μm using a continuous-wave color center laser. A high-finesse triangular ring cavity is used in this technology. Transmission through the cavity is obtained by jittering the cavity-length with a piezo on one of the cavity mirrors. A minimum detectable absorption coefficient of 2 × 10-6 cm-1 is achieved with a mirror reflectivity of 99.24%, corresponding to a N2O detection limit of 600 parts per billion.