Study on novel light absorption layer of LCLV

Abstract

A novel light absorption layer for liquid crystal light valve is developed by VOPc and a new structure of liquid crystal light valve by using a three-sources evaporation system is proposed. CdTe is a typical absorption layer for liquid crystal light valve, but its absorption coefficient is not so good, especially at 400nm-500nm. However, the absorption of VOPc is very good at this range. So VOPc is introduced to the multi absorption layer. Then a double-layer absorption layer with a good absorption at whole visible light range can be got. To increase the adherence to the substrate, an SiO layer is introduced to wrap the CdTe layer and VOPc layer like a sandwich structure. At first SiO layer is evaporated and then the CdTe layer and the VOPc layer at the same time. After finishing the CdTe layer, VOPc is continuously evaporated for a while and then evaporating the CdTe is again made. After finishing CdTe and VOPc layer, SiO layer is used to cover the whole layer. At last, a multi light absorption layer with 8000a thick and the structure of SiO:CdTe:VOPc:CdTe:SiO is deposited on glass by evaporation technique. Dependence of light absorption coefficient of multi film is measured. The resistivity of novel absorption layer is 5.5 10 8 Ω•cm. The absorption coefficient of R =7.8 10 5 cm 1 , G =6.8 10 5 cm 1 , and B =7.2 10 5 cm 1 is obtained with the optimum technics through experiment, and it can meet the needs of the liquid crystal light valve.