White Electroluminescence from a Microcontact-Printing-Deposited CdSe/ZnS Colloidal Quantum-Dot Monolayer

A new approach, based on microcontact printing (μCP) was proposed for fabricating CdSe/ZnS colloidal quantum-dot (QD) monolayer. The approach used a SU-8 photoresist, as a protective layer for the PDMS, to conduct investigations. The new approach was used to fabricate a multilayer, white-light-emitting diode (LED. The advantage of using SU-8 led to the possibility for deposition, by using an easy and low-cost spin-coating process. The PDMS mold was prepared by casting it onto the top of a blank silicon master. The stamp was removed from the master after curing and SU-8 was spin-coated onto the top. The SU-8 was exposed to ultraviolet (UV) radiation and thermally cross linked to make the film insoluble to toluene. A mixed blue, green, and red CdSe/ZnS- QD solution was also spin-coated onto the SU-8 protected PDMS.