(Bi,　Sb)2Te3　based　materials　have　been　commercially　utilized　in　the　field　of　solid　refrigeration,　but　their　application　on　power　generation　requires　further　improvement　of　thermoelectric　and　mechanical　properties　at　elevated　temperatures.　This　work　reveals　a　kind　of　high-performance　and　robust　Sb2Te3　based　alloys　operating　above　550　K.　Starting　with　the　optimized　composition　In0.1Sb1.9Te3,　nanograins　and　nanotwins　are　constructed　by　high　energy　ball　milling　and　some　boron　particles　are　added　to　impede　the　boundary　softening　caused　by　the　grain　refinement.　On　this　basis,　oversaturated　copper　(Cu)　doping　is　employed　to　introduce　both　point　defects　and　nanoprecipitates,　further　leading　to　a　full-spectrum　phonon　scattering　and　extraordinary　low　lattice　thermal　conductivity.　Besides,　some　Cu　atoms　replace　Sb　atoms　to　increase　the　carrier　concentration　and　thus　suppress　the　intrinsic　excitation,　while　some　others　locate　at　twin　boundaries　as　interstitials　to　accelerate　the　carrier　migration　between　two　adjacent　twin　variants,　collectively　contributing　to　significant　improvement　of　power　factor.　Ultimately,　the　zT　value　of　Cu0.015B0.05In0.1Sb1.885Te3　is　increased　above　1.0　between　573　and　673　K.　This　material　is　very　suitable　for　segmentation　with　optimized　Bi0.5Sb1.5Te3　alloys　well　operating　at　lower　temperatures,　leading　to　high　device　ZT　exceeding　1.05　within　330–673　K,　as　well　as　high　conversion　efficiency　up　to　12.7%　under　temperature　difference　of　370　K.　©　2020　Elsevier　Ltd