The Study Of Infrared Protective C/Ge_1-xC_x Films And Their Application On As₄₀Se₆₀ Chalcogenide Glasses

Infrared protective antireflective film can enhance the resistance of infrared windows to sand and dust,rain,chemical corrosion and other harsh environmental condition.Meanwhile,infrared protective antireflective film can promote the transmittance of infrared windows and optimize the image of infrared system.Whereas,the traditional infrared protective antireflective film shows high residual stress and is deposited under high temperature,all of these drawbacks limit its application on the temperature sensitive chalcogenide glasses with high expansion coefficient.The structural,mechanical and optical properties of infrared protective film deposited by rf magnetic sputtering under low temperature hasn't been studied comprehensively.Thus,the above problems have been exhaustive studied in this thesis and the main results are summarized as follows:1.Effect of CH4 flow rate on properties of amorphous carbon film:The deposition temperature is lower than 115?.The adaptable highly hydrogenated graphite-like amorphous carbon?GLCHH?films were fabricated on As40Se60chalcogenide glass by rf MS using CH4 as precursor.The deposition neutrals and radical ions decomposed from CH₄ precursor unfold the fused aromatic rings of sp² clusters and transform them to olefinic chains and transforms the amorphous carbon films from DLC structure to GLCHH structure.GLCHH films enhance the long-wave?8?12?m?infrared transmittance of As40Se60 glass substrate from 62.51%to 70.90%.The nanohardness of As₄₀Se₆₀0 glass substrate increases from 1.9 GPa to3.6 GPa,the residual stress decreases from 1.29 GPa to 0.20 GPa.2.Effect of sputtering power on the properties of Ge_1-xC_x film:The amorphous Ge_1-xC_x films were deposited on As₄₀Se₆₀0 glass by rf MS co-sputtering under low temperature?<75??.The increasing power reduces the C-Ge sp³ hybridization structure,encourages the transformation of olefinic chains and nc-graphite to fused aromatic rings with nucleation function of Ge atoms,increases the disorder state of amorphous carbon phase,facilitates the construction of sp³ hybridization structure of Ge_1-xC_x films.Meanwhile,the nanohardness of Ge_1-xC_x films is elevated from 4.1 GPa to 12.1 GPa,residual stress of Ge_1-xC_x films is transformed from tensile stress to compressive stress as sputtering power increases from 50 W to 450 W.The protective antireflective Ge_1-xC_x?150 W?/DLC double layers improve the average transmittance and nanohardness of As40Se60 glass from62.2%to 72.6%?3?5?m?and 1.9 GPa to 7.8 GPa,respectively.3.Effect of Ge content on the properties of Ge_1-xC_x film:The increasing Ge content consumes the C atoms to configure the Ge-C sp³ bonds.The consumption of C-C sp²structure is faster than C-C sp³structure,olefinic chains and nc-graphite prefer to be consumed by Ge atoms comparing to fused aromatic rings as Ge content increases from 18.36%to 49.71%.As Ge content increases from66.46%to 78.88%,all the carbon clusters are depleted,there are only Ge-C sp³ and Ge-Ge sp³phase within the Ge_1-xC_x film.The nanohardness of Ge_1-xC_x film increases from 6.9 GPa to 9.9 GPa as Ge content increases from 18.36%to 78.88%.Ge_1-xC_x?66.46%?/DLC double layer promotes the longwave infrared band?8?11?m?mean transmittance of As40Se60 chacogenide glass from 61.3%to 66.4%.4.Effect of sputtering target on properties of Ge1-x Cx film:Ge_1-xC_x films sputtered from hot-pressed sintered Ge-C target shows much lower infrared absorption than films sputtered from Ge-inserted graphite mixed target,which is due to the uniform distribution of Ge and C atoms.5.The application of the combination of antireflective film?AR?and Ge_1-xC_x/GLCHH film.The highly antireflective and protective AR/As₄₀Se₆₀/AR+Ge_1-xC_x/GLCHH film enhances the longwave?8?11?m?average transmittance of As₄₀Se₆₀0 chacogenide glass from 61.3%to 94.0%,the highest transmittance is 95.9%.The above researches have solved the core issue of‘low temperature deposited,well adhesive protective antireflective films on chalcogenide glass'.Researches have revealed the function of Ge and H atoms to amorphous carbon clusters,and their related mechanical and optical properties under low temperature,which is innovative.the present thesis could be useful for reference on studying the low temperature deposited optical films on temperature sensitive substrate.