Strain Engineering to Release Trapped Hole Carriers in p-Type Haeckelite GaN
Strain Engineering to Release Trapped Hole Carriers in p-Type Haeckelite GaN
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DOI：
10.1021/acsaelm.1c00765
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发表时间：
2021-11
影响因子：
4.7
通讯作者：
Soungmin Bae;Y. Kang;K. Ichihashi;M. Khazaei;V. Swamy;M. Han;K. Chang;K. Shudo;H. Raebiger
中科院分区：
文献类型：
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作者：
Soungmin Bae;Y. Kang;K. Ichihashi;M. Khazaei;V. Swamy;M. Han;K. Chang;K. Shudo;H. Raebiger
氮化镓黑云母（4| 8-GaN）相是用于二维（2D）发光二极管（LED）的有吸引力的材料;然而，由于空穴载流子捕获，其p型掺杂仍然具有挑战性。我们的密度泛函理论计算表明，应变工程作为一种途径，以释放被困的空穴载流子。我们发现，Mg和Be杂质在4| 8-GaN具有多种空穴态，包括破缺极化子（捕获）和离域（扩展）态，其对Mg和Be杂质的脱陷能量估计分别为33.4和263.3 meV。然而，通过施加垂直于4 ° C的约2%的适度拉伸应变，可以使被Mg杂质俘获的空穴态脱陷。|8平面，这将极大地增强p型掺杂性。我们进一步表明，Mg杂质的光致发光（PL）光谱可以通过晶格应变进行调谐，这使得能够有效地控制4| 8-GaN。我们的研究结果为设计基于4的原子薄蓝光LED铺平了道路。|8-GaN。
The gallium nitride haeckelite (4|8-GaN) phase is an attractive material for a two-dimensional (2D) light-emitting diode (LED); however, its p-type doping is still challenging due to hole carrier trapping. Our density functional theory calculations suggest strain engineering as a route to release trapped hole carriers. We show that Mg and Be impurities in 4|8-GaN have multifarious hole states, including symmetry-broken polaronic (trapped) and delocalized (extended) states, whose detrapping energies are estimated to be 33.4 and 263.3 meV for Mg and Be impurities, respectively. The hole states trapped by a Mg impurity can be, however, detrapped by applying a moderate tensile strain around 2% perpendicular to the 4|8 plane, which would critically enhance p-type dopability. We further show that the photoluminescence (PL) spectrum of a Mg impurity can be tuned by the lattice strain, which enables efficient control for light emission of 4|8-GaN. Our findings pave the way to design an atomically thin blue LED based on 4|8-GaN.