硼墨烯的化学合成及其光电性能研究

Borophenes are tried to synthesize by chemical vapor transportation and chemical vapor deposition with appropriate boron source, and the structures will be characterized, and synthesized method will be refined to realize low-cost and high yield, and the materials can be controllably synthesized. And then as-prepared borophenes are dispersed on SiO2/Si substrate, and then four or two-electrodes are fabricated on a single borophene by a photolithography to form field effect transistor. Subsequently, relativity of resistance to temperature will be measured to confirm type of conductors, and transistor characteristic under room temperature will be measured including semiconducting type, carrier concentration, mobility, and so on. The photoresponses under different strengths and frequencies, detectivities, and on-off ratio and response time under a defined frequency and strength of light, will be measured. The photoresponse and photoswitching ratio in vacuum, nitrogen, and air will be measured to probe for mechanism producing photocurrents, laying a foundation for material applications.

采用合适的硼源(如乙硼烷、卤化硼等)，用化学气运传输和化学气相沉积等方法制备硼墨烯，并完成结构表征、合成方法的优化以及实现低成本、高产量的可控合成。然后，将合成的硼墨烯分散在SiO2/Si基片上，用光刻技术在单片硼墨烯上，加工四电极或两电极构成场效应晶体管，测量变温电阻判断导电类型，测量室温晶体管性质包括半导体类型、载流子浓度、迁移率等；测量在不同频率相同光照强度下的光响应、光探测性以及在某一频率和光照强度下的光开光和响应时间。在真空、空气和氮气环境下研究晶体管的光响应与光开关效应，以分析光电流产生的机制，为材料的应用奠定基础。

二维材料的研究是当前材料科学研究的重要方向。硼墨烯是新近获得的的非层状的二维材料，理论计算表明它具有金属性，并有希望在电子与光伏领域获得应用。然而目前的制备方法多为离子溅射法，并且缺乏实验上的光电性能测试，因此，它的化学制备与光电性能的研究尤为重要。为此我在两年内进行了三方面的尝试工作：（1）BBr3热分解法制备硼烯与表征。在封闭石英管中，在光学级的石英基片上，沉积硼烯，已获得0.5-3.4 nm厚度，平面尺度10-20 nm的颗粒膜；（2）在管壁上沉积获得厚度约13.8 nm, 平面尺寸为几十微米的硼纳米纸；（3）在HfS3纳米线上沉积硼烯量子点以及光电性能。而且工作仍在继续，这为硼烯的深入研究奠定基础。