Synthesis and Transfer of Large-Area Monolayer WS2 Crystals: Moving Toward the Recyclable Use of Sapphire Substrates
Synthesis and Transfer of Large-Area Monolayer WS2 Crystals: Moving Toward the Recyclable Use of Sapphire Substrates
复制标题
大面积单层 WS2 晶体的合成和转移：迈向蓝宝石衬底的可回收利用
DOI：
10.1021/acsnano.5b01480
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发表时间：
2015-06-01
期刊：
影响因子：
17.1
通讯作者：
Bao, Qiaoliang
中科院分区：
文献类型：
--
作者：
Xu, Zai-Quan;Zhang, Yupeng;Bao, Qiaoliang
二维层状过渡金属二硫属化物（TMD）由于其奇异的电子和光学特性，在光电器件方面显示出令人着迷的潜力。只有少数努力致力于 TMD 的大面积生长。实际应用需要通过（1）新的生长方法以不太严格的条件生产大尺寸TMD单层，以及（2）能够多次重复使用生长基板的无损转移技术来提高效率并降低生产成本。在这项工作中，我们报告采用常压化学气相沉积（APCVD）在蓝宝石衬底上合成大尺寸（>100μm）单晶原子薄二硫化钨（WS2），TMD家族的成员。更重要的是，我们证明了通过水中毛细管力的聚苯乙烯（PS）介导的分层过程，c-蓝宝石减少了基础溶液中的蚀刻时间，并且对蓝宝石衬底仅造成轻微损坏。转移的 WS2 薄片具有出色的连续性，并且在重复使用的蓝宝石基板上经过几个生长周期后表现出相当的电子迁移率。有趣的是，在回收蓝宝石上生长的 WS2 的光致发光发射远高于新鲜蓝宝石，这可能是由于在回收蓝宝石衬底的原子台阶处插入了一层薄薄的水，对单层 WS2 薄片进行了 p 型掺杂。这里描述的生长和转移技术预计适用于其他原子薄 TMD 材料。
Two-dimensional layered transition metal dichalcogenides (TMDs) show intriguing potential for optoelectronic devices due to their exotic electronic and optical properties. Only a few efforts have been dedicated to large-area growth of TMDs. Practical applications will require improving the efficiency and reducing the cost of production, through (1) new growth methods to produce large size TMD monolayer with less-stringent conditions, and (2) nondestructive transfer techniques that enable multiple reuse of growth substrate. In this work, we report to employ atmospheric pressure chemical vapor deposition (APCVD) for the synthesis of large size (>100 mu m) single crystals of atomically thin tungsten disulfide (WS2), a member of TMD family, on sapphire substrate. More importantly, we demonstrate a polystyrene (PS) mediated delamination process via capillary force in water which c-Sapphire reduces the etching time in base solution and imposes only minor damage to the sapphire substrate. The transferred WS2 flakes are of excellent continuity and exhibit comparable electron mobility after several growth cycles on the reused sapphire substrate. Interestingly, the photoluminescence emission from WS2 grown on the recycled sapphire is much higher than that on fresh sapphire, possibly due to p-type doping of monolayer WS2 flakes by a thin layer of water intercalated at the atomic steps of the recycled sapphire substrate. The growth and transfer techniques described here are expected to be applicable to other atomically thin TMD materials.