中文摘要：

采用化学气相沉积法（CVD）在铜箔上制备石墨烯,与n型硅（n-Si）形成石墨烯/n-Si异质结并研究了该结构的光伏和光响应性能。采用拉曼光谱和高分辨透射电镜（HRTEM）分析对石墨烯的结构进行了表征,并通过制备和测试石墨烯场效应晶体管考察了石墨烯的电学性能。采用光刻、等离子刻蚀等工艺将石墨烯与n-Si结合制备成异质结,在标准光源下对其光电性能进行测试。结果表明石墨烯为单层且呈现p型输运特性,载流子迁移率为3900 cm2·V-1·s-1。在无光照条件下,石墨烯/n-Si异质结表现出较好的整流特性。加上光照之后,表现出良好的光伏性能,开路电压和短路电流分别为0.28 V和0.87 m A,填充因子为0.37。同时该异质结在光响应测试中表现出非常快的响应速度和良好的稳定性,光源开启和关闭时的弛豫时间分别为96.9和84.9 ms,且在多个循环之后电流大小保持不变。对石墨烯/n-Si异质结良好的光响应及光伏特性的机制进行了简要分析,认为石墨烯高的电子迁移率及良好的光透过性起到了关键性作用。

英文摘要：

Graphene films were obtained on copper substrates by chemical vapor deposition（ CVD）,graphene / n-Siheterojunctions were produced by transferring graphene films onto n-Sisubstrates,and the photoresponse and photovoltaic properties in graphene / n-Siheterojunction were investigated. The structure of graphene was characterized by Raman spectrum and high-resolution transmission electron microscopy（ HRTEM）. Graphene field effect transistor was also produced to investigate the electrical properties of graphene. Using photolithography and plasma etching process,the graphene / n-Siheterojunctions were prepared. The optical and electrical properties of the heterojunction were tested under standard light source. The results demonstrated that the as-grown graphene was single layer and showed p-type field effect with a field-effect mobility of 3900 cm2·V- 1·s- 1at room temperature. The graphene / n-Siheterojunction showed good rectification characteristics and excellent photovoltaic properties. The open circuit voltage and short-circuit current were0. 28 V and 0. 87 m A,respectively,and the filled factor was 0. 37. The heterojunction also showed good response capability and stability. The rise time was 96. 9 ms and the decay time was 84. 9 ms. The current remained unchanged after multiple cycles,showing good stability and response capability. The mechanism of the heterojunction with good photoresponse and photovoltaic properties was analyzed and it was considered that high electron mobility and good optical transparency of graphene played key roles.