Optical Properties Of Low-dimensional Phase Change Film Display Devices

The display technology based on phase-change material has the characteristics of high color contrast,high resolution,high speed,low power consumption and so on.In this paper,the optical properties of the display device based on phase-change material and the back light source prepared by the LED remote fluorescent technology based on the electrostatic spinning process are studied.The phase-change material(GST)is applied to the display device,and the influence of the thickness and the change of the state of the GST layer and the thickness of upper and lower layers of ITO on the optical properties of the display device are analyzed.The display device based on the phase change material can't emit light,and it needs a backlight source to illuminate.The ideal light source is the full spectrum light source.Light source prepared by LED remote fluorescence technique based on electrospinning process when using PET plastic film,can produce a uniform surface light source,and the flexible sheet can easy integrated With display panel.The fluorescent powder prepared by the process is uniformly dispersed in the space network structure formed by the PVA nano fiber to prevent agglomeration.The transfer matrix calculation model was used to study a unique display employing low-dimensional phase-change thin film(PCMs).The main influence factors of the display device based on the phase change material(GST)include the thickness and the change of the state of the GST layer,and the thickness of the upper and lower layers of the ITO.The conclusions of the study are as follows:For reflection type devices,the reflection spectra of the devices with different ITO thickness under different layers are very large.When the state of GST is changed,the reflection spectrum of the device is changed,and the color of the device will be also changed.Whether GST is in the crystal or amorphous state,the thickness of the upper layer of ITO does not affect the wavelength of the maximum reflectivity.When GST is in different conditions,the maximum reflectivity corresponding to the wavelengths is different.When the thickness of GST 11nm is 11nm,the electric energy consumed is the least and the device has the best color contrast.For transmission type devices,when the thickness of the GST film layer is increased,the transparency of the device is reduced.Therefore,in the design of the device structure,in order to take into account the color contrast and transparency of the device,we can choose the area 7nm-15nm as a compromise.The preparation technology and optical properties of the fluorescent film were studied.We draw the following conclusions:When the PVA concentration is 9%,the voltage is 25kV,from the spinneret to slide distance is 9cm,are three the optimal parameters of the electrospinning process,and effect of spinning is the most obvious.The yellow phosphor and red phosphor were prepared by electrospinning process,and the optical properties were tested and analyzed.The transmittance of the yellow phosphor can be tested by using the spectrophotometer,and the light transmittance of the LED remote fluorescent sheet based on the electrostatic spinning process is very good.The PL spectrum of the yellow fluorescent film can be measured by the fluorescence spectrum measurement system,and the peak value of the spectrum is not changed with the different time of the electrostatic spinning time.Therefore,we can prepare the fluorescent films with different electrospinnirig time to achieve the desired effect and optical properties.Optical performance parameters of lamp can be measured by fast spectrum radiometer:luminous flux,color temperature and light effect.The longer periods of time for electrospinning,the lower for the flux,and the light efficiency is low at the same time.The fluorescent film using different fluorescent powder content can keep high efficiency,and achieve a wide range of color temperature adjustment at the same time.Therefore,the red fluorescent lamp can be used to adjust the luminous spectral components of the lamp and improve the lighting quality.