The research progress on each functional layer material of quantum dot light emitting diodes (QLEDs) fabricated by the spin-coating method are reviewed.The characteristics and applications of various materials for carrier injection layers and transport layers prepared by spincoating are compared and summarized.Numerous studies show that the inorganic metal oxide materials (ZnO,TiO2,etc) are superior to organic materials in the electron mobility and device reliability as the electron transport layer (ETL),and the organic polymer materials (poly [double (4-phenyl) (4-butyl phenyl) amine] (Poly-TPD),poly (9-vinyl carbazole) (PVK),etc) with higher hole mobility and better film quality are more widely used as the hole transport layer (HTL).Moreover,a few inorganic metal oxide materials such as MoOx and WOx,etc are widely used as the hole injection layer due to their better energy level matching and higher reliability.With the technology maturity and the demands of higher efficiency and higher reliability in QLEDs applications,inorganic metal oxide materials prepared by low-cost spin-coating method will become more and more widespread,which will promote the commercialization of QLEDs.

The paper designed and developed GaAs-based RTD (Resonant Tunneling Diode), which can achieve a high peak-to-valley current ratio of 7.6:1 at room temperature. Then it made on-wafer measurement for S parameter of RTD, analyzed frequency characteristics of RTD and the equivalent circuit parameters are obtained by fitting in order to calculate the maximum oscillation frequency. Resonant tunneling diode AC smallsignal model was established to be used for circuit simulation and the paper utilized PSPICE for analog simulation with analogue result coincidental with experimental data. Lastly it used negative resistance value to estimate switch time according to I-V characteristics and compared with other two methods, conclude that the reasonable switch time is about 0.8|RN|Cd.

The transfer matrix calculation model was used to study a unique display device emplo-ying low-dimensional phase-change thin film ( PCMs) . The optical properties of the device based on the germanium antimony tellurium alloy Ge2 Sb2 Te5 ( GST) thin films were studied by simulation. It was showed how such a system, when combined with a transparent electrode such as indium tin ox-ide ( ITO) , could be used as displays on reflective and transparent substrates both on rigid and flexi-ble surfaces. To understand the relationship between the thickness of ITO and GST layers and the overall optical properties of the stack, the reflectivity spectrum of the stack was systematically com-puted while the thickness of each layer was gradually increased. For the reflection type device, the thickness of ITO has great influence on the reflection spectrum of the device, and the color of the device can be changed by changing the thickness of ITO. When the thickness of GST is 12 nm, the color contrast of the device is the best which is achieved by changing the phase of GST between amorphous and crystalline, and the power consumption is low. For the transmission type device, the transparency of the device can be very high by using ultra-thin GST film, but the transparency de-clines rapidly when the thickness of GST is more than a few nanometers.