渐变Ni-AlN选择性吸收涂层的中频溅射技术研究

Study on Medium-Frequency Sputtering of Graded Ni-AlN Selective Absorbers

探讨Ni-AlN复合膜和渐变Ni-AlN选择性吸收涂层的中频溅射技术。结果表明:随着镍靶电流增加和铝靶电流减小,铝靶溅射由金属模式向反应模式转变对应的临界氮气流量降低,制备的Ni-AlN复合膜中镍含量增加,铝含量和氮/铝原子比减少,更容易产生游离铝。随着单层复合材料吸收层沉积时间的增加,Ni-AlN选择性吸收涂层由梯度渐变结构变成多层膜结构,在可见光范围的反射率降低;当单层复合材料吸收层沉积时间为10min时,Ni-AlN选择性涂层在可见光范围的反射率约为10%,具有良好的光谱选择性。

The influence of medium-frequency sputtering process on the structure of Ni-AlN composite films and graded Ni-AlN selective absorbers was studied. Results show that the critical nitrogen flow rates are decreased corresponding to the change of aluminum sputtering mode from metallic mode to reactive mode with increasing nickel target current and decreasing aluminum target current; the nickel content in Ni-AlN composite films is increased with the rise of nickel target current, while the variety of the aluminum content and N/Al atomic ratio with nickel target current is inverse; metallic aluminum phase is apt to be formed in the Ni-AlN composite films deposited at higher nickel target current. When the deposition duration for a Ni-AlN composite layer is increased, the composition distribution of Ni-AlN selective absorbers in depth is shifted from the gradual changing to the stepped changing, and the visible light reflectivity is decreased. A visible light reflectivity of about 10% and a good spectral selectivity is obtained when the deposition duration for a Ni-AlN composite layer is 10 min.