Room-temperature pulsed oscillation with a laser wavelength of 290nm and a threshold current density of 35kAcm⁻² was achieved by fabricating a UV-B laser diode on a thick AlGaN film formed on a 1μm periodic concavo–convex pattern AlN (PCCP-AlN) on a sapphire substrate. The advantage of this method using PCCP-AlN is that it promotes the nucleation of AlGaN crystals. Planarization of this growth nucleus with AlGaN reduces the threading dislocation density at the top of the AlGaN growth layer while suppressing the formation of giant micrometer-sized hillocks and V-shaped pits that appear irregularly.

中文翻译：

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用290nm的的1波长AlGaN基UV-B的激光二极管μ中号周期性凹凸图案的AlN在蓝宝石衬底上

室温脉冲振荡与290nm的的激光波长和35kAcm的阈值电流密度^-2是由制造在形成于一个1厚的AlGaN膜的UV-B的激光二极管实现μ中号周期性凹凸图案的AlN（PCCP- AlN）在蓝宝石衬底上。这种使用 PCCP-AlN 的方法的优点是它促进了 AlGaN 晶体的成核。用 AlGaN 对这种生长核进行平面化，降低了 AlGaN 生长层顶部的穿透位错密度，同时抑制了不规则出现的巨大微米级小丘和 V 形凹坑的形成。