The influence of threading dislocations propagating through an AlGaN UVC LED

During the epitaxy of AlGaN on sapphire for deep UV emitters, significant lattice mismatch leads to highly strained heterojunctions and the formation of threading dislocations. Combining cathodoluminescence, electron beam induced current and x-ray microanalysis reveal that dislocations with a screw component permeate through a state-of-the-art UVC LED heterostructure into the active region and perturb their local environment in each layer as growth progresses. In addition to acting as non-radiative recombination centers, these dislocations encourage high point defect densities and three-dimensional growth within their vicinity. We find that these point defects can add parasitic recombination pathways and compensate intentional dopants. (C) 2022 Author(s).

在用于深紫外发射器的蓝宝石上外延氮化铝镓（AlGaN）期间，显著的晶格失配导致高度应变的异质结以及螺型位错的形成。结合阴极荧光、电子束诱导电流和X射线微分析表明，具有螺型分量的位错穿透最先进的深紫外C（UVC）发光二极管异质结构进入有源区，并随着生长的进行扰乱每层的局部环境。除了作为非辐射复合中心外，这些位错还促使其附近的高点缺陷密度和三维生长。我们发现这些点缺陷会增加寄生复合路径并补偿有意掺杂的杂质。（C）2022作者。