Reshchikov M A, Andrieiev O, Vorobiov M, Ye D, Demchenko D O, McEwen B, Shahedipour-Sandvik F
Department of Physics, Virginia Commonwealth University, Richmond, VA 23220, United States of America.
Department of Nanoscale Science and Engineering, SUNY-Albany, Albany, NY 12203, United States of America.
Nanotechnology. 2025 Jan 7;36(10). doi: 10.1088/1361-6528/ada298.
GaN is an important semiconductor for energy-efficient light-emitting devices. Hydrogen plays a crucial role in gallium nitride (GaN) growth and processing. It can form electrically neutral complexes with acceptors during growth, which significantly increases the acceptor incorporation. Post-growth annealing dissociates these complexes and is widely utilized for activating Mg acceptors and achieving conductive p-type GaN. In this work, we demonstrate that other acceptors, such as C and Be, also form complexes with hydrogen similar to Mg. The effect of thermal annealing of GaN on photoluminescence (PL) was investigated. In samples moderately doped with Be, the Be-related yellow luminescence (YL) band intensity decreased by up to an order of magnitude after annealing in Nambient at temperatures= 400 °C-900 °C. This was explained by the release of hydrogen from unknown traps and the passivation of the Beacceptors. A similar drop of PL intensity at= 350 °C-900 °C was observed for the C-related YL1 band in unintentionally C-doped GaN and also attributed to passivation of the Cacceptors by hydrogen released from unknown defects. In this case, the formation of the CHcomplexes was confirmed by the observation of the rising BL2 band associated with these complexes. At> 900 °C, both the YLand YL1 intensities were restored, which was explained by the removal of hydrogen from the samples. Experimental results were compared to the first principles calculations of complex dissociation and hydrogen diffusion paths in GaN.
氮化镓是用于节能发光器件的一种重要半导体。氢在氮化镓（GaN）的生长和加工过程中起着至关重要的作用。在生长过程中，它能与受主形成电中性络合物，这显著增加了受主的掺入量。生长后退火会使这些络合物解离，并且被广泛用于激活镁受主以及实现导电的p型氮化镓。在这项工作中，我们证明了其他受主，如碳和铍，也会与氢形成类似于镁的络合物。研究了氮化镓热退火对光致发光（PL）的影响。在适度掺杂铍的样品中，在400℃至900℃的氮气环境中退火后，与铍相关的黄色发光（YL）带强度下降了一个数量级之多。这是由于氢从未知陷阱中释放以及铍受主的钝化所致。在非故意掺杂碳的氮化镓中，对于与碳相关的YL1带，在350℃至900℃时也观察到了类似的PL强度下降，这同样归因于从未知缺陷中释放的氢对碳受主的钝化。在这种情况下，通过观察与这些络合物相关的BL2带的上升证实了CH络合物的形成。在高于900℃时，YL和YL1强度都恢复了，这是由于样品中氢的去除所致。将实验结果与氮化镓中络合物解离和氢扩散路径的第一性原理计算进行了比较。
