Effect of the ZnS Shell Layer on the Electrical Properties of Organic Bistable Devices Fabricated Utilizing CdSe/CdS/ZnS Core-Shell-Shell Quantum Dots Embedded in a Poly(methylmethacrylate) Layer

摘要

X-ray photoelectron spectroscopy spectra showed that the synthesized elements of the CdSe/CdS/ZnS QDs were Cd, Se, Zn, and S. Organic bistable devices (OBDs) containing CdSe/CdS/ZnS quantum dots (QDs) and a poly(methylmethacrylate) (PMMA) layer were fabricated on indiumtin-oxide (ITO)-deposited glass substrates. Current-voltage (I-V) curves showed that the memory margin of the Al/(CdSe/CdS/ZnS QDs) embedded in PMMA layer/ITO device at 300 K was larger than that of the device without a ZnS shell layer. The retention time of the OBDs was above 1x10(4) s, indicative of the stability of the device. The memory mechanisms were described by using charge trapping and tunneling processes on the basis of the energy diagram and the I-V curves.