Calabrese Gabriele, Pimpolari Lorenzo, Conti Silvia, Mavier Fabrice, Majee Subimal, Worsley Robyn, Wang Zihao, Pieri Francesco, Basso Giovanni, Pennelli Giovanni, Parvez Khaled, Brooks David, Macucci Massimo, Iannaccone Giuseppe, Novoselov Kostya S, Casiraghi Cinzia, Fiori Gianluca
Dipartimento di Ingegneria dell'Informazione, Università di Pisa, Pisa 56122, Italy.
Department of Chemistry, University of Manchester, Manchester M13 9PL, UK.
Nanoscale. 2020 Mar 28;12(12):6708-6716. doi: 10.1039/c9nr09289g. Epub 2020 Mar 18.
We report room temperature Hall mobility measurements, low temperature magnetoresistance analysis and low-frequency noise characterization of inkjet-printed graphene films on fused quartz and SiO/Si substrates. We found that thermal annealing in vacuum at 450 °C is a necessary step in order to stabilize the Hall voltage across the devices, allowing their electrical characterization. The printed films present a minimum sheet resistance of 23.3 Ω sq after annealing, and are n-type doped, with carrier concentrations in the low 10 cm range. The charge carrier mobility is found to increase with increasing film thickness, reaching a maximum value of 33 cm V s for a 480 nm-thick film printed on SiO/Si. Low-frequency noise characterization shows a 1/f noise behavior and a Hooge parameter in the range of 0.1-1. These results represent the first in-depth electrical and noise characterization of transport in inkjet-printed graphene films, able to provide physical insights on the mechanisms at play.
我们报告了在熔融石英和SiO/Si衬底上喷墨打印石墨烯薄膜的室温霍尔迁移率测量、低温磁阻分析和低频噪声表征。我们发现，在450°C的真空中进行热退火是稳定器件上霍尔电压以便进行电学表征的必要步骤。退火后，打印薄膜的最小方块电阻为23.3Ω/sq，且为n型掺杂，载流子浓度处于低10¹²cm⁻³范围。发现电荷载流子迁移率随薄膜厚度增加而增大，对于在SiO/Si上打印的480nm厚薄膜，其最大值为33cm²/V·s。低频噪声表征显示出1/f噪声行为，且霍格参数在0.1 - 1范围内。这些结果代表了对喷墨打印石墨烯薄膜输运进行的首次深入电学和噪声表征，能够为其中起作用的机制提供物理见解。
