| The polymer dispersed liquid crystal(PDLC)switchable film has the characteristics of intelligence,energy saving and privacy protection,and is widely used in fields such as flexible display screens,optical attenuators and smart partition walls.The commonly used electrode material of PDLC switchcable film is ITO film,but ITO is difficult to meet the low cost and curling requirements of switchable film due to its high price and intrinsic brittleness,and the Ag-based tri-layer film with excellent transparent conductive properties is a good substitute.Therefore,the preparation process of PDLC switchable films were first explored in this thesis.And then,the GZO/Ag/GZO tri-layer film were prapared by magn etron sputtering,and the structure and transparent conductive properties of the films were investugated.Finally,the properties of the switchable films based on electrode of GZO/Ag/GZO tri-layer film were investigated.The main research content of the thesis and the results obtained are as follows:(1)The preparation and properties of heat cured epoxy resin based PDLC and UV cured acrylate based PDLC were studied.By adjusting the raw material ratio and curing process,the epoxy based PDLC with Toff of 7.05%,Ton of 66.6%,Vth of 17V,and Vsat of 33V and acrylate based PDLC with Toff of 1.66%,Ton of 76.67%,Vth of 20V,and Vsat of 41V were obtained,respectively.Due to the simple preparation process and excellent switchable properties of UV cured acrylate based PDLC,it is appropriate to select this material system and related processes to prepare the switchable film.(2)The effect of sputtering power(20-80W)on the structure and properties of the GZO/Ag/GZO tri-layer film during the deposition of the Ag layer was discussed.It is found that the increase in the sputtering power of the Ag layer reduces the critical thickness of continuous film formation.However,when the Ag layer deposited under different sputtering powers reaches the critical thickness,the optimized transparent conductive properties of the GZO/Ag/GZO tri-layer film are basically equivalent.Based on investigation above,the sputtering power of the Ag layer was fixed at 40 and 80 W,respectively,and the influences of N21 flow rate on the structure and properties of the Ag layer and GZO/Ag/GZO thri-layer films were further studied.The results show that the introduction of N2 can promote the formation of the continuous Ag layer,and thus results in the GZO/Ag/GZO tri-layer films having better transparent conductive properties at relatively thinner thickness(the Ag layer thickness is only 2-3nm at sputtering power of 80 W and N2 flow rate of 6-8sccm).In addition,it is also found that the overall performance of the tri-layer film can also be improved to a certain extent when a 0.5 nm thick Ag(N)layer(i.e.,deposited in an atmosphere containing N2)is first deposited before depositoin of Ag layer.(3)The performance of UV-curing acrylate-based PDLC switchable film with the GZO/Ag/GZO tri-layer film as the transparent electrode was studied.Although the prepared GZO/Ag/GZO tri-layer films have better transparent conductive properties than those of ITO film,switchable films with the GZO/Ag/GZO tri-layer film as the transparent electrode have almost equivalent Toff and Vth,significantly lower Ton(lower than about 10%)and higher Vsat(higher than about 20 V)compared with the switchable films with ITO film as the transparent electrode.The significantly lower Ton of the switchable film based on GZO/Ag/GZO films as electrode may be related to the tri-layer structure of the electrode.Even so,compared with the swithcable films with electrode materials such as graphene,silver nanowires and Cu-based tri-layer film,the switchable films with GZO/Ag/GZO as the electrode still has certain advantages in terms of overall performance,which exhibits their potential application prospects. |
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