Red light emitting solid state hybrid quantum dot-near-UV GaN LED devices

摘要

We produced core - shell (CdSe) ZnSe quantum dots by direct colloidal chemical synthesis and the surface-passivation method - an overcoating of the core CdSe with a larger-bandgap material ZnSe. The ( CdSe) ZnSe quantum dots(QDs) play the role of a colour conversion centre. We call these quantum dots nanophosphors. We fabricated red light emitting hybrid devices of ( CdSe) ZnSe QDs and a near-UV GaN LED by combining red light emitting ( CdSe) ZnSe quantum dots ( as a colour conversion centre) with a near-UV(NUV) GaN LED chip ( as an excitation source). A few good red phosphors have been known for UV excitation wavelengths, and red phosphors for UV excitation have been sought for a long time. Here we tested the possibility of using ( CdSe) ZnSe QDs as red nanophosphors for UV excitation. The fabricated red light emitting hybrid device of ( CdSe) ZnSe and a NUV GaN LED chip showed a good luminance. We demonstrated that the ( CdSe) ZnSe quantum dots were promising red nanophosphors for NUV excitation and that a red LED made of QDs and a NUV excitation source was a highly efficient hybrid device.