Park Byoungchoo, Lee Won Seok, Na Seo Yeong, Huh Jun Nyeong, Bae In-Gon
Department of Electrical and Biological Physics, Kwangwoon University, Wolgye-Dong, Nowon-gu, Seoul, 01897, Republic of Korea.
Sci Rep. 2019 Apr 19;9(1):6328. doi: 10.1038/s41598-019-42800-y.
Surface-emitting organic light-emitting transistors (OLETs) could well be a core element in the next generation of active-matrix (AM) displays. We report some of the key characteristics of graphene-based vertical-type organic light-emitting transistors (Gr-VOLETs) composed of a single-layer graphene source and an emissive channel layer. It is shown that FeCl doping of the graphene source results in a significant improvement in the device performance of Gr-VOLETs. Using the FeCl-doped graphene source, it is demonstrated that the full-surface electroluminescent emission of the Gr-VOLET can be effectively modulated by gate voltages with high luminance on/off ratios (~10). Current efficiencies are also observed to be much higher than those of control organic light-emitting diodes (OLEDs), even at high luminance levels exceeding 500 cd/m. Moreover, we propose an operating mechanism to explain the improvements in the device performance i.e., the effective gate-bias-induced modulation of the hole tunnelling injection at the doped graphene source electrode. Despite its inherently simple structure, our study highlights the significant improvement in the device performance of OLETs offered by the FeCl-doped graphene source electrode.
表面发射有机发光晶体管（OLETs）很可能成为下一代有源矩阵（AM）显示器的核心元件。我们报告了由单层石墨烯源和发光沟道层组成的基于石墨烯的垂直型有机发光晶体管（Gr-VOLETs）的一些关键特性。结果表明，石墨烯源的FeCl掺杂导致Gr-VOLETs的器件性能有显著改善。使用FeCl掺杂的石墨烯源，证明了Gr-VOLET的全表面电致发光发射可以通过具有高亮度开/关比（约10）的栅极电压有效地调制。即使在超过500 cd/m的高亮度水平下，电流效率也被观察到远高于对照有机发光二极管（OLEDs）。此外，我们提出了一种运行机制来解释器件性能的改善，即在掺杂的石墨烯源电极处有效栅极偏压诱导的空穴隧穿注入调制。尽管其结构本质上很简单，但我们的研究突出了FeCl掺杂的石墨烯源电极在OLETs器件性能方面的显著改善。
