Growth of semipolar GaN laser diodes (LDs) on low-cost and large-size foreign substrates is crucial yet remains very challenging. In this study, we report the world’s first continuous-wave (CW) electrically driven semipolar blue LDs at room temperature heteroepitaxially grown on a 4-in. sapphire substrate. The semipolar (202̅1) GaN material grown on sapphire substrate exhibits high crystal quality from the X-ray diffraction and transmission electron microscopy measurements. The AlGaN-cladding free semipolar blue LDs utilizing thin p-GaN/indium tin oxide (ITO) cladding structure show a lasing peak at 456 nm, a threshold current density of 6.1 kA/cm², and a high output power (P₀) of 1.03 W at 2.8 A under pulsed operation condition. Moreover, the semipolar blue LDs exhibit a CW P₀ of 243 mW at room temperature. The emission light from the semipolar blue LDs is 100% polarized. These results mark a significant breakthrough in substantially reducing the cost of semipolar LDs and expediting the development of future semipolar GaN LDs and their applications.

中文翻译：

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在蓝宝石衬底上异质外延生长的室温连续波电驱动半极性（202̅1）蓝色激光二极管

在低成本和大尺寸异物衬底上生长半极性GaN激光二极管（LD）至关重要，但仍然非常困难。在这项研究中，我们报告了世界上第一个在室温下异质外延生长在4英寸上的连续波（CW）电驱动半极性蓝色LD。蓝宝石衬底。通过X射线衍射和透射电子显微镜测量，在蓝宝石衬底上生长的半极性（202̅1）GaN材料显示出高晶体质量。利用薄p-GaN /铟锡氧化物（ITO）覆层结构的无AlGaN覆层的半极性蓝色LD在456 nm处出现激射峰，阈值电流密度为6.1 kA / cm ²且输出功率高（P ₀）在2.8 A的脉冲操作条件下为1.03 W. 此外，半极性蓝色LD在室温下的CW P ₀为243 mW。来自半极性蓝色LD的发射光是100％偏振的。这些结果标志着在大幅降低半极性LD成本和加快未来半极性GaN LD及其应用开发方面的重大突破。