A quantum well intermixing(QWI) investigation on double quantum well(DQW) structure with two different emitting wavelength caused by phosphorus ion implantation and following rapid thermal annealing(RTA) was carried out by means of photoluminescence(PL). The ion implantation was performed at the energy of 120keV with the dose ranging from 1×10~11cm~-2 to 1×10~14cm~-2. The RTA was performed at the temperature of 700℃ for 30s under pure nitrogen protection. The PL measurement implied that the band gap blue-shift from the upper well increases with the ion dose faster than that from lower well and the PL peaks from both QWs remained well separated under the lower dose implantation(～1×10~11cm~-2) indicating that the implant vacancy distribution affects the QWI. When the ion dose is over ～1×10~12cm~-2, the band gap blue-shift from both wells increases with the ion dose and finally the two peaks merge together as one peak indicating the ion implantation caused a total intermixing of both quantum wells. A quantum well intermixing (QWI) investigation on double quantum well (DQW) structure with two different emission wavelength caused by phosphorus ion implantation and following rapid thermal annealing (RTA) was carried out by means of photoluminescence (PL). The ion implantation was performed at the energy of 120  keV with the dose ranging from 1 × 10 ~ 11  cm ~ -2 to 1 × 10 ~ 14 cm ~ 2. The RTA was performed at the temperature of 700  ℃ for 30 s under pure nitrogen protection. The PL measurement implied that the band gap blue-shift from the upper well increases with the ion dose faster than that from lower well and the PL peaks from both QWs remained well separated under the lower dose implantation (~1 × 10 ~ 11 cm ~ 2) indicating that the implant vacancy distribution affects the QWI. When the ion dose is over ~ 1 × 10 ~ 12 cm ~ 2, the band gap blue-shift from both wells increases with the ion dose and finally the two peaks merge together as one peak indicating the ion implantation caused a total intermixing of both quantum wells.