Atomic‐Scale Investigation of the Lattice‐Asymmetry‐Driven Anisotropic Sublimation in GaN. Issue 22 (2nd June 2022)

• Record Type: Journal Article
• Authors: Sheng, Shanshan; Wang, Tao; Liu, Shangfeng; Liu, Fang; Sheng, Bowen; Yuan, Ye; Li, Duo; Chen, Zhaoying; Tao, Renchun; Chen, Ling; Zhang, Baoqing; Yang, Jiajia; Wang, Ping; Wang, Ding; Sun, Xiaoxiao; Zhang, Jingmin; Xu, Jun; Ge, Weikun; Shen, Bo; Wang, Xinqiang
• Is Part Of: Advanced science. Volume 9:Issue 22(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-06-02
• Subjects: anisotropic sublimation -- equilibrium crystal structure -- in situ transmission electron microscope -- wurtzite gallium nitride; Science -- Periodicals; 505
• DOI: 10.1002/advs.202106028
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Thermal sublimation, a specific method to fabricate semiconductor nanowires, is an effective way to understand growth behavior as well. Utilizing a high‐resolution transmission electron microscope (TEM) with in situ heating capability, the lattice‐asymmetry‐driven anisotropic sublimation behavior is demonstrated of wurtzite GaN: sublimation preferentially occurs along the [ 000 1 ¯ $000\bar{1}$ ] and [0001] directions in both GaN thin films and nanowires. Hexagonal pyramidal nanostructures consisting of six semipolar { 1 1 ¯ 01 } $\{ {1\bar{1}01} \}$ planes and one (000 1 ¯ $\bar{1}$ ) plane with the apex pointing to the [0001] direction are generated as a sublimation‐induced equilibrium crystal structure, which is consistent with the lattice‐asymmetry‐driven growth behaviors in wurtzite GaN. These findings offer a new insight into the thermal stability of wurtzite GaN and provide essential background for tailoring the structure of III‐nitrides for atomic‐scale manufacturing. Abstract : Anisotropic sublimation behavior of wurtzite GaN is directly demonstrated using in situ heating transmission electron microscopy (TEM) technique. Sublimation preferentially occurs along [0001] and [ 000 1 ¯ $000\bar{1}$ ] directions. A hexagonal pyramid with the apex pointing to [0001] direction is generated as the sublimation‐induced equilibrium crystal structure of wurtzite GaN. The observed phenomena is attributed to the asymmetric surface energies in wurtzite GaN.