α-ZnS(R+/R-~ 0.225-0.414)（Wurtzite/纤锌矿/六方硫化锌）Packing of anions:hcpPosition of cations:Tetrahedral holes (1/2)hexagonal PBravais lattice:4:4C.N. of A- & B+:NA:Np in a unit cell: 2:2Zn,S2Structural motif:A: (0,0,0);(1/3, 2/3, 1/2)B: (0, 0, 3/8); (1/3, 2/3, 7/8)CuF, CuCl, CuBr, Cul; Agl; ZnO, ZnS, ZnSe, ZnTe; CdO.CdS, CdSe, CdTe; HgS, HgSe, HgTe, (CoO, MnO)
A: (0,0,0); (1/3, 2/3, 1/2) B: (0, 0, 3/8); (1/3, 2/3, 7/8) (Wurtzite/纤锌矿/六方硫化锌) a-ZnS (R+ /R- ~ 0.225-0.414) CuF, CuCl, CuBr, CuI; AgI; ZnO, ZnS, ZnSe, ZnTe; CdO, CdS, CdSe, CdTe; HgS, HgSe, HgTe, (CoO, MnO) • Packing of anions: hcp • Position of cations: Tetrahedral holes (1/2) • Bravais lattice: hexagonal P • C.N. of A- & B+ : 4:4 • NA :NB in a unit cell: 2:2 • Structural motif: Zn2S2
Example: ZnO ---- Growth of unusual morphologiesCrystal structure of ZnO(Wurtzite type)Zn+2Ypolar(000)polar (0001[0001][2110]0(1010), (0110), (1100), (2110)Non-polar surfaces:The polar surfaces (0001) and (0001) have higher surfaceenergies than other non-polar surfaces do!
Example: ZnO - Growth of unusual morphologies Crystal structure of ZnO (Wurtzite type) dipole moment ㊀ ㊀ ㊀ ㊀ ㊀ ㊀ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊀ ㊀ ㊀ ㊀ ㊀ ㊀ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊀ ㊀ ㊀ ㊀ ㊀ ㊀ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊀ ㊀ ㊀ ㊀ ㊀ ㊀ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊀ ㊀ ㊀ ㊀ ㊀ ㊀ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊀ ㊀ ㊀ ㊀ ㊀ ㊀ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊀ ㊀ ㊀ ㊀ ㊀ ㊀ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊀ ㊀ ㊀ ㊀ ㊀ ㊀ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ c The polar surfaces (0001) and (0001) have higher surface energies than other non-polar surfaces do! [2110] –– – – Non-polar surfaces: (1010), (0110), (1100), (2110) – – – –– [0001] [0001]– –
Non-polar[100]Normalgrowth田①田Polar surface (001Growthdirection0-2axisZn+2nmGrowing into rod-like morphology along c axis to give rise tothose stable non-polar surfaces exposed
c axis ㊀ ㊉ ㊀ ㊉ ㊀ Growth direction Normal growth Non-polar{100} Growing into rod-like morphology along c axis to give rise to those stable non-polar surfaces exposed
gg = 20.00 K 1Thermo CVD of ZnO onMicro-wave plasma CVD ofSilicon surfacesZnO on Silicon surfaces100.0020.2μmthermo-decomposing52nmZn(CH,COO),2nmZnO tends to grow into nanowires with [oo0l] as growth direction
ZnO tends to grow into nanowires with [0001] as growth direction. Thermo CVD of ZnO on Silicon surfaces Micro-wave plasma CVD of ZnO on Silicon surfaces thermo-decomposing Zn(CH3COO)2
Control the surface energy by Electrostatic interactionPlate-likewithGrowthdirection{001) surfaceD0fexposed甲甲甲甲田田田甲Saturated田solution ofsaltGrowthMg-150.00KxHdirectionPENIBEETWD-3m2233:12Zn+0o1surfacesexposed
Control the surface energy by Electrostatic interaction Plate-like with {001} surface ㊀ ㊉ ㊀ ㊉ ㊀ exposed ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ ㊉ Growth direction Growth direction {001} surfaces exposed Saturated solution of salt