The　Sn-doped　ZnO(T-SZO)　clusters　with　tetrapod-shaped　structures　were　synthesized　by　thermal　evaporation　of　highly　pure　Sn　and　Zn　powders　in　air.The　effect　of　the　tetrapod　growth　time,on　the　microstructures　and　field　emission　characteristics　was　investigated　with　X-ray　diffraction,X-ray　photoelectron　spectroscopy,scanning　electron　microscopy　and　photoluminescence　spectroscopy.The　results　show　that　the　growth-time　significantly　affects　the　microstructures　and　field　emission　properties　of　the　hexagonal　wurtzite-phased　T-SZO　tetrapodes　with　Sn-content　below　1%(at).To　be　specific,as　the　growth-time　increased　from　2　to　5　min,both　the　large-sizedand　small-sized　tetrapodes　grew,thickening　and　elongating　with　an　increasing　aspect-ratio.Heated　for　4min,the　octopod-shaped　clusters　were　observed.The　tetrapod-shaped　T-SZO　clusters　with　sharp　tip-apex　and　high　aspect-ratio　of　25　were　grown　for　5　min;　and　the　favorable　field　emission　properties　included:an　onset　field　of　1.81　V/μm,a　threshold　field　of　3.0　V/μm　and　a　field　enhancement　factor　of　6770.　©　2016,　Science　Press.　All　right　reserved.