A zinc oxide ZnO field emitter-based backlight unit for liquid crystal display with a gated structure is fabricated by screen-printing processes.The measured anode field emission current density reaches 0.62 mA/cm2 when the applied gate voltage is 570 V.Part of the anode current is contributed by the secondary electron emission which is excited from the MgO layer inside the gate apertures on the gate plate. The average emission current density and luminance are 0.47 mA/cm2 and 1 250 cd/m2 respectively with a fluctuation of about 10% during the 1 000 min measurement.By a finite element method calculation the gated structure shows a good electron beam focusing property. The driving performance of the backlight unit is characterized by SPICE simulation tools and measured by the oscilloscope. Stable field emission line-by-line scanning and fast response characteristics of the backlight unit indicate its promising application in the liquid crystal displays.
We reviewed the key advantages and development of the QD-display and other light applications based on their color purity,stability,and solution processisibility.Analysis of quantum dot based LEDs and the main challenges facing in this field,such as QD luminescence quenching,QD charging in thin films,and the external quantum efficiency was presented in detail.The description about how different optical down-conversion and structures enabled researchers to overcome these challenges and to commercialize the products to achieve the desirable CRI and color temperature was presented.The recent developments about how to overcome these difficulties have also been discussed in this article.
