Department of Mechanical Engineering, University of California, Riverside, CA 92521, USA.
Nanotechnology. 2011 Sep 2;22(35):355701. doi: 10.1088/0957-4484/22/35/355701. Epub 2011 Aug 5.
We studied the photodesorption behavior of pristine and nitric acid (HNO(3)) treated graphene layers fabricated by chemical vapor deposition (CVD). The decrease in electrical conductivity and a negative shift of the Dirac point in graphene layers illuminated with ultraviolet light are caused by molecular photodesorption, while the UV illumination does not degrade the carrier mobility of graphene layers. When graphene layers were treated with concentrated HNO(3), the photodesorption-induced current decrease became less significant than for pristine graphene layers. We suggest this is due to the passivation of oxygen-bearing functionalities to CVD grown graphene structural defects by HNO(3) functionalization, which prevents the further absorption of gas molecules. Our results provide a new strategy for stabilizing the electrical performance of CVD grown large-area graphene layers for applications ranging from nanoelectronics to optoelectronics.
我们研究了通过化学气相沉积（CVD）制备的原始和经硝酸（HNO3）处理的石墨烯层的光解吸行为。在紫外光照射下，分子光解吸导致石墨烯层的电导率降低和狄拉克点负移，而紫外光照射不会降低石墨烯层的载流子迁移率。当石墨烯层用浓 HNO3 处理时，光解吸诱导的电流下降比原始石墨烯层小。我们认为这是由于 HNO3 功能化对 CVD 生长的石墨烯结构缺陷中的含氧官能团进行了钝化，从而阻止了更多的气体分子的吸收。我们的结果为稳定从纳米电子学到光电子学等应用的 CVD 生长大面积石墨烯层的电性能提供了一种新策略。
