Since　the　luminance　of　Micro-LEDs　is　highly　dependent　on　the　injected　current　density,　inevitable　voltage　fluctuations　will　lead　to　luminance　fluctuations　and　weak　luminance　robustness.　In　this　work,　Micro-LED　chips　working　in　non-electrical　contact　and　non-carrier　injection　(NEC　and　NCI)　mode　is　proposed,　which　is　totally　different　from　the　current-injected　mode.　The　luminance　of　NEC　and　NCI　Micro-LEDs　first　increases　with　the　increase　of　the　voltage,　and　the　saturation　luminance　can　be　obtained　during　a　relatively　large　voltage　range,　which　is　defined　as　an　operating　voltage　window.　Then　the　luminance　decreases　when　the　voltage　is　further　increased.　It　is　demonstrated　that　the　operating　voltage　windows　can　enhance　luminance　robustness.　Finally,　the　insulating　layer　that　is　crucial　for　the　operating　voltage　windows　is　optimized.　And　the　working　mechanisms　related　to　the　existence　of　operating　voltage　windows　are　discussed.　©　1963-2012　IEEE.