射频磁控溅射法制备Cu_2SnS_3薄膜结构和光学特性的研究

Synthesis and Optical Properties of Magnetron Sputtered Cu_2SnS_3 Thin Films

利用射频磁控溅射法并经快速退火处理制备Cu_2SnS_3薄膜,研究了使用SnS_2、Cu_2S混合靶(摩尔比分别为1∶1、1∶1.5、1∶2)及在不同溅射功率(40和80W)条件下所制备Cu_2SnS_3薄膜的晶体结构、物相组成、化学组分、表面形貌和光学特性。结果表明:混合靶的SnS_2、Cu_2S最佳摩尔比为1∶1.5,利用该靶所制备薄膜均结晶;在溅射功率为80 W条件下,所制备薄膜结晶质量和择优取向度高,应变最小,Cu∶Sn∶S摩尔比为1.89∶1∶2.77,平均颗粒直径和平均粗糙度分别为332和0.742 nm,吸收系数达到10~4cm^(-1),禁带宽度为1.32 eV。制备了n-Si/p-CTS异质结器件,器件具有良好的整流特性和光电流响应特性。

The Cu2SnS3（ CTS） thin films were deposited by RF magnetron puttering of a lab-made SnS2/Cu2S target. The impact of the molar ratio of SnS2/Cu2S powders and sputtering power on the microstructures,stoichiometric ratio and optical properties of the CTS coating was investigated with X-ray diffraction,energy dispersive spectroscopy,atomic force microscopy,Raman spectroscopy and UV/VIS/NIR spectroscopy. The preliminary results show that high quality CTS coatings were deposited under the optimized conditions. To be specific,grown at a molar ratio of 1∶ 1. 5 and a sputtering power of 80 W,the polycrystalline tetragonal-phase CTS coatings consisted of 213 preferentially orientated grains with average grain-size of 332 nm,surface roughness of 0. 742 nm and stoichiometric ratio of 1. 89（ Cu） ∶ 1（ Sn） ∶ 2. 77（ S）. The absorption coefficient and band-gap were 10^4cm^-1 and 1. 32 eV respectively. Moreover,the n-Si/p-CTS hetero-junction,made of the low strain CTS coatings,displayed good properties of rectifying and photocurrent response.