Chen Kun, Deng Shiyu, Chen Enzi, Wen Shiya, Ouyang Tenghui, Wang Ximiao, Zhan Runze, Cai Jixing, Wan Xi, Chen Huanjun
State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology and Guangdong Province Key Laboratory of Display Material, Sun Yat-sen University, Guangzhou 510275, China.
Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, China.
ACS Appl Mater Interfaces. 2021 Sep 22;13(37):44814-44823. doi: 10.1021/acsami.1c14519. Epub 2021 Sep 8.
Chemical vapor deposition (CVD) is a promising method to obtain monolayer transition metal dichalcogenides (TMDCs) with high quality and enough size to meet the requirements of practical photoelectric devices. However, the as-grown monolayers often exhibit a lower PL performance due to the stress between the as-grown TMDCs flakes and the substrate. Therefore, finding a facile method to effectively promote the photoluminescence quantum yield (PL QY) of CVD monolayer TMDCs with a clean surface is highly desirable for practical applications. In this work, based on the CVD monolayers MoS and MoSe, the effect of various stress relaxation methods on the TMDCs PL enhancement is systemically studied. By comparing the different kinds of volatile solution treatment processes, as well as the traditional transfer process, it can be found that the volatile solution with a moderate volatilization rate such as ethanol or IPA is a preferred option to improve the PL performance of the CVD monolayer TMDCs, which also surpasses the traditional transfer method by avoiding wrinkles, defects, and contamination to the samples. PL QY of ethanol-treated CVD samples could increase by 6 times on average. Significantly, PL QY of CVD MoSe treated by ethanol can reach ∼16%, which is at the forefront of the previous reports of 2D MoSe. Our study demonstrated an optimized method to enhance the PL QY of CVD monolayer TMDCs, which would facilitate TMDCs optoelectronics.
化学气相沉积（CVD）是一种很有前景的方法，可用于获得高质量且尺寸足够大的单层过渡金属二硫属化物（TMDCs），以满足实际光电器件的要求。然而，由于生长的TMDCs薄片与衬底之间的应力，生长出的单层往往表现出较低的光致发光性能。因此，找到一种简便的方法来有效提高具有清洁表面的CVD单层TMDCs的光致发光量子产率（PL QY）对于实际应用来说是非常有必要的。在这项工作中，基于CVD单层MoS和MoSe，系统地研究了各种应力松弛方法对TMDCs光致发光增强的影响。通过比较不同种类的挥发性溶液处理过程以及传统转移过程，可以发现具有适度挥发速率的挥发性溶液，如乙醇或异丙醇，是提高CVD单层TMDCs光致发光性能的首选，它还通过避免样品出现褶皱、缺陷和污染而超过了传统转移方法。乙醇处理的CVD样品的PL QY平均可提高6倍。值得注意的是，乙醇处理的CVD MoSe的PL QY可达~16%，这在二维MoSe的先前报道中处于领先地位。我们的研究展示了一种优化方法来提高CVD单层TMDCs的PL QY，这将推动TMDCs光电子学的发展。
