基底及HMVF层厚度变化对NbSiN/NbSiNO/Si_3N_4涂层光学性能的影响

INFLUNENCE OF THE SUBSTRATE AND THICKNESS OF HMVF LAYERS ON PERFORMANCE OF NbSiN/NbSiNO/Si_3N_4 TANDEM

采用多靶磁控溅射镀膜机,以在Si靶上加Nb片的方法分别在Cu和单面抛光不锈钢(SS)基底上制备NbSiN/NbSiNO/Si3N4和Mo/NbSiN/NbSiNO/Si3N4多层膜。用α-step台阶仪(DEKTAK IIA)测量膜层厚度,UVPC3100分光光度计和傅里叶红外光谱仪(EXCALIBUR FTS 3000)对样品的光学性质进行表征。实验表明:在Cu基底上制备的涂层吸收率α=0.90,发射率ε=0.12;以SS为基底,红外反射层Mo的厚度约为230nm时,在λ>2.5μm范围内反射率最高,达到90%以上。高金属体积分数吸收层(HMVF)厚度约为80nm时吸收率α=0.95,发射率ε=0.33;真空下500℃和600℃各20h退火后吸收率、发射率变化不大。

NbSiN/NbSiNO/Si3N4 and Mo/NbSiN/NbSiNO/Si3N4 muhilayer Films were deposited on single-sided polishing stainless steel and Cu substrates by a reactive magnetron sputtering system. Four Nb chips （99.95%,Φ60mm ×3mm） were put on the polysilicon target. The thickness and optical performance were investigated by DEKTAK IIA X-step, UVPC3100 spectrophoto-meter and EXCALIBUR FTS 3000 Fourier Transform Infrared Spectrophotometer （FTIR）. It was found that a high solar absorptance （0. 90） and low emittance （0. 12） on Cu substrate has been obtained. Infrared reflectance is relatively high when Mo layer thickness is 230nm at 〉2. 5μm of wavelength. The surfaces exhibits high absorptance α = 0. 95 and emittance ε = 0. 33 when high metal fraction volume （HMVF） layer thickness is about 80nm. The coating remains stable in vacuum up to 600℃ for 20 hours. Keywords： solar energy ; spectrally selective ; optical properties ; absorptance ; emittance ; magnetron sputtering