利用选择性外延法生长单芯片双波长白光InGaN/GaN多量子阱结构

为了制备单芯片无荧光粉白光InGaN/GaN多量子阱发光结构,利用选择性外延生长法在SiO2条纹掩膜板上生长出具有梯形形貌的GaN微面结构,并在该GaN微面结构上生长InGaN/GaN多量子阱结构,最终在单芯片上获得了双波长发光.结果表明:梯形GaN微面由(0001)和(11-22)面组成,两者的表面能和极性不同,并且在InGaN/GaN多量子阱生长过程中,In原子和Ga原子迁移速率不同,从而使得(0001)和(11-22)面上的多量子阱具有不同的发光波长;该性质可以使(11-22)面的微面量子阱发出蓝光(峰值波长为420nm),而(0001)面的量子阱发出黄光(峰值波长为525nm),最终形成双波长的复合白光外延结构.

Growth of Single-chip Dual-wavelength White-light InGaN/GaN Multiple Quantum Wells by Using the Selective Epitaxial Growth Method

In order to fabricate the phosphor-free InGaN/GaN multiple quantum wells (MQWs) with white light emission,the GaN microfacets with trapezoidal structure were grown using SiO2 stripe mask patterns,and then the InGaN/GaN multiple quantum wells (MQWs) were regrown on the GaN microfacets,forming dual-wavelength emissions in a single chip.The results indicate that,the trapezoidal GaN microfacet is composed of (0001) and (11-22) planes,which is attributed to the differences of surface polarity and surface energy.Also,the different color emissions on (0001) and (11-22) planes are due to the different diffusion rates of In and Ga adatoms;this property allows microfacet MQWs emit blue light (emission peak at 420 nm) from the (11-22) plane and yellow light (emission peak at 525 nm) from the top (0001) plane,the mixing of which leads to the perception of white light emission.