The bilayer devices using a mixture film of triplet emitting material Cu 4(C≡CPh 4) 4L 2[L=1,8 bis(diphenyl phosphino) 3,6 dioxaoctane](Cu 4) and hole transport polymer poly(9 vinylcarbazole)(PVK) as emitting layer, electron transport material TAZ as the electron transport layer were prepared. Different devices that formed by varied Cu 4 ratios show different light emitting properties through singlet triplet and triplet triplet energy transfer. The result showed a new application of triplet emitting materials.