Ritchie Cameron, Chesman Anthony S R, Styles Mark, Jasieniak Jacek J, Mulvaney Paul
ARC Centre of Excellence in Exciton Science, School of Chemistry and Bio21 Institute, University of Melbourne , 30 Flemington Road, Parkville, Victoria 3010, Australia.
ARC Centre of Excellence in Exciton Science, Materials Science and Engineering, and Energy Materials & Systems Institute, Monash University , 20 Research Way, Clayton, Victoria 3800, Australia.
Langmuir. 2018 Jan 30;34(4):1655-1665. doi: 10.1021/acs.langmuir.7b03885. Epub 2018 Jan 19.
Copper zinc tin sulfide (CZTS) nanocrystal inks are promising candidates for the development of cheap, efficient, scalable, and nontoxic photovoltaic (PV) devices. However, optimization of the synthetic chemistry to achieve these goals remains a key challenge. Herein we describe a single-step, aqueous-based synthesis that yields high-quality CZTS nanocrystal inks while also minimizing residual organic impurities. By exploiting simultaneous redox and crystal formation reactions, square-platelet-like CZTS nanocrystals stabilized by SnS and thiourea are produced. The CZTS synthesis is optimized by using a combination of inductively coupled plasma analysis, Raman spectroscopy, Fourier transform infrared spectroscopy, and synchrotron powder X-ray diffraction to assess the versatility of the synthesis and identify suitable composition ranges for achieving phase-pure CZTS. It is found that mild heat treatment between 185 and 220 °C is most suitable for achieving this because this temperature range is sufficiently high to thermalize existing ligands and ink additives while minimizing tin loss, which is problematic at higher temperatures. The low temperatures required to process these nanocrystal inks to give CZTS thin films are readily amenable to production-scale processes.
硫化铜锌锡（CZTS）纳米晶体油墨是开发廉价、高效、可扩展且无毒的光伏（PV）器件的有前途的候选材料。然而，优化合成化学以实现这些目标仍然是一个关键挑战。在此，我们描述了一种单步水基合成方法，该方法可生产高质量的CZTS纳米晶体油墨，同时还能将残留有机杂质降至最低。通过利用同步氧化还原和晶体形成反应，制备出了由SnS和硫脲稳定的方形片状CZTS纳米晶体。通过结合电感耦合等离子体分析、拉曼光谱、傅里叶变换红外光谱和同步辐射粉末X射线衍射来优化CZTS的合成，以评估合成的通用性并确定实现纯相CZTS的合适组成范围。发现185至220°C之间的温和热处理最适合实现这一点，因为该温度范围足够高，可以使现有的配体和油墨添加剂热解，同时将锡损失降至最低，而锡损失在较高温度下是个问题。将这些纳米晶体油墨加工成CZTS薄膜所需的低温很容易适用于生产规模的工艺。
