[1] SAITO Y, TAKAO H, TANI T et al. Lead-free piezoceramics[J]. Nature, 432, 84-87(2004).

[2] ZHAO M H, WANG Z L, MAO S X. Piezoelectric characterization of individual zinc oxide nanobelt probed by piezoresponse force microscope[J]. Nano Letters, 4, 587-590(2004).

[3] WANG Z L. Nanostructures of zinc oxide[J]. Materials Today, 7, 26-33(2004).

[4] WU W, WANG L, LI Y et al. Piezoelectricity of single-atomic-layer MoS₂ for energy conversion and piezotronics[J]. Nature, 514, 470(2014).

[5] DAI M, WANG Z, WANG F et al. Two-dimensional van der Waals materials with aligned in-plane polarization and large piezoelectric effect for self-powered piezoelectric sensors[J]. Nano Letters, 19, 5410-5416(2019).

[6] DUERLOO K A N, ONG M T, REED E J. Intrinsic piezoelectricity in two-dimensional materials[J]. The Journal of Physical Chemistry Letters, 3, 2871-2876(2012).

[7] LI W, LI J. Piezoelectricity in two-dimensional group-III monochalcogenides[J]. Nano Research, 8, 3796-3802(2015).

[8] PRODHOMME P Y, BEYA-WAKATA A, BESTER G. Nonlinear piezoelectricity in wurtzite semiconductors[J]. Physical Review B, 88, 121304(2013).

[9] JANOTTI A, VAN DE WALLE C G. Fundamentals of zinc oxide as a semiconductor[J]. Reports on Progress in Physics, 72, 126501(2009).

[10] STRITE S, MORKOÇ H. GaN. AlN, and InN: a review[J]. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena, 10, 1237-1266(1992).

[11] ZHANG J, WANG C, BOWEN C. Piezoelectric effects and electromechanical theories at the nanoscale[J]. Nanoscale, 6, 13314-13327(2014).

[12] ZHOU J, GU Y, FEI P. Flexible piezotronic strain sensor[J]. Nano Letters, 8, 3035-3040(2008).

[13] AGRAWAL R, ESPINOSA H D. Giant piezoelectric size effects in zinc oxide and gallium nitride nanowires: a first principles investigation[J]. Nano Letters, 11, 786-790(2011).

[14] MOGULKOC A, MOGULKOC Y, MODARRESI M et al. Electronic structure and optical properties of novel monolayer gallium nitride and boron phosphide heterobilayers[J]. Physical Chemistry Chemical Physics, 20, 28124-28134(2018).

[15] TUSCHE C, MEYERHEIM H L, KIRSCHNER J. Observation of depolarized ZnO(0001) monolayers: formation of unreconstructed planar sheets[J]. Physical Review Letters, 99, 026102(2007).

[16] TOPSAKAL M, CAHANGIROV S, BEKAROGLU E et al. First-principles study of zinc oxide honeycomb structures[J]. Physical Review B, 80, 235119(2009).

[17] SHU H, NIU X, DING X et al. Effects of strain and surface modificaion on stability, electronic and optical properties of GaN monolayer[J]. Applied Surface Science, 479, 475-481(2019).

[18] KRESSE G, FURTHMÜLLER J. Efficiency ofab-initio total energy calculations for metals and semiconductors using a plane-wave basis set[J]. Computational Materials Science, 6, 15-50(1996).

[19] KRESSE G, FURTHMüLLER J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set[J]. Physical Review B, 54, 11169(1996).

[20] PERDEW J P, BURKE K, ERNZERHOF M. Generalized gradient approximation made simple[J]. Physical Review Letters, 77, 3865(1996).

[21] VANDERBILT D. Berry-phase theory of proper piezoelectric response[J]. Journal of Physics and Chemistry of Solids, 61, 147-151(2000).

[22] HEYD J, SCUSERIA G E, ERNZERHOF M. Hybrid functionals based on a screened Coulomb potential[J]. The Journal of Chemical Physics, 118, 8207-8215(2003).

[23] HONG H K, JO J, HWANG D et al. Atomic scale study on growth and heteroepitaxy of ZnO monolayer on graphene[J]. Nano Letters, 17, 120-127(2017).

[24] PENG Q, LIANG C, JI W et al. A first principles investigation of the mechanical properties of g-ZnO: the graphene-like hexagonal zinc oxide monolayer[J]. Computational Materials Science, 68, 320-324(2013).

[25] PENG Q, LIANG C, JI W et al. Mechanical properties of g-GaN: a first principles study[J]. Applied Physics A, 113, 483-490(2013).

[26] WEI X, FRAGNEAUD B, MARIANETTI C A et al. Nonlinear elastic behavior of graphene: ab initio calculations to continuum description[J]. Physical Review B, 80, 205407(2009).

[27] LUENG C M, CHAN H L W, SURYA C et al. Piezoelectric coefficient of aluminum nitride and gallium nitride[J]. Journal of Applied Physics, 88, 5360-5363(2000).

[28] XU S, QIN Y, XU C et al. Self-powered nanowire devices[J]. Nature Nanotechnology, 5, 366-373(2010).