Lee Ping Han, Brahma Sanjaya, Dutta Jit, Huang Jow-Lay, Liu Chuan-Pu
Department of Materials Science and Engineering, National Cheng Kung University Tainan 701 Taiwan
Hierarchical Green-Energy Materials (Hi-GEM) Research Center, National Cheng Kung University Tainan 70101 Taiwan.
Nanoscale Adv. 2021 May 21;3(13):3909-3917. doi: 10.1039/d0na01069c. eCollection 2021 Jun 30.
We demonstrate the synergistic effects of Ga doping and Mg alloying into ZnO on the large enhancement of the piezopotential and stress sensing performance of piezotronic pressure sensors made of Ga-doped MgZnO films. Piezopotential-induced pressure sensitivity was enhanced through the modulation of the Schottky barrier height. Doping with Ga (0.62 Å) of larger ionic radius and alloying with Mg (0.57 Å) of smaller ionic radius than Zn ions can synergistically affect the overall structural, optical and piezoelectric properties of the resulting thin films. The crystal quality of Ga-doped MgZnO films either improved ( ≦ 0.041) or deteriorated ( ≧ 0.041) depending on the Ga doping concentration. The band gap increased from 3.90 eV for pristine MgZnO to 3.93 eV at = 0.076, and the piezoelectric coefficient ( ) improved from ∼23.25 pm V to ∼33.17 pm V at an optimum Ga concentration ( = 0.027) by ∼2.65 times. The change in the Schottky barrier height Δ increased from -4.41 meV (MgZnO) to -4.81 meV ( = 0.027) and decreased to -3.99 meV at a high Ga doping concentration ( = 0.041). The stress sensitivity (0.2 kgf) enhanced from 28.50 MPa for the pristine MgZnO to 31.36 MPa ( = 0.027) and decreased to 25.56 MPa at higher Ga doping concentrations, indicating the synergistic effects of Ga doping and Mg alloying over the pressure sensing performance of Ga-doped MgZnO films.
我们展示了在ZnO中进行Ga掺杂和Mg合金化对由Ga掺杂的MgZnO薄膜制成的压电器件的压电势和应力传感性能大幅增强的协同效应。通过肖特基势垒高度的调制增强了压电势诱导的压力敏感性。与Zn离子相比，具有较大离子半径的Ga（0.62 Å）掺杂和具有较小离子半径的Mg（0.57 Å）合金化可以协同影响所得薄膜的整体结构、光学和压电性能。根据Ga掺杂浓度，Ga掺杂的MgZnO薄膜的晶体质量要么提高（≦0.041）要么恶化（≧0.041）。带隙从原始MgZnO的3.90 eV增加到= 0.076时的3.93 eV，并且在最佳Ga浓度（= 0.027）下，压电系数（）从23.25 pm V提高到33.17 pm V，提高了约2.65倍。肖特基势垒高度的变化Δ从-4.41 meV（MgZnO）增加到-4.81 meV（= 0.027），并在高Ga掺杂浓度（= 0.041）下降低到-3.99 meV。应力灵敏度（0.2 kgf）从原始MgZnO的28.50 MPa提高到31.36 MPa（= 0.027），并在更高的Ga掺杂浓度下降低到25.56 MPa，这表明Ga掺杂和Mg合金化对Ga掺杂的MgZnO薄膜的压力传感性能具有协同效应。
