In　order　to　resolve　the　problems　existing　in　the　conventional　phosphor-converted　light-emitting-diodes　(LEDs)　and　red-green-blue　LEDs,　the　cascade　single-chip　phosphor-free　white　LED　was　proposed　with　GaAs/GaN　heterojunction　direct　wafer　bonding.　Corresponding　to　the　color-matching　calculation,　the　white　LED　demonstrated　the　CIE　chromaticity　coordinates　of　about　(0.3,　0.3)　at　20　mA,　which　was　very　close　to　the　ideal　white　light　position　(1/3,　1/3)　on　the　chromaticity　diagram.　The　fabrication　and　the　electrical　and　optical　performances　of　such　white　LEDs　were　described.　(c)　2008　American　Institute　of　Physics.