Effect of Organic Dopants in Dimetallophthalocyanine Thin Films: Application to Optoelectronic Devices

• 作者: José Ramón álvarez-Bada María Elena Sánchez-Vergara Pablo Osorio-Lefler Santiago Osorio-Lefler
• 来源期刊: 材料物理与化学进展(英文)
• 学科: 化学
• 关键词: ORGANIC SEMICONDUCTORS THIN Films Optical PROPERTIES Electrical PROPERTIES OPTOELECTRONIC Devices
• 年，卷（期）: clwlyhxjzyw_2019,（4）
• 页码范围: 71-88
• 页数: 18页
• 分类号: O6

摘要

Semiconductor films of organic, doped dimetallophthalocyanine M2Pcs (M = Li, Na) on different substrates were prepared by synthesis and vacuum evaporation. Tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ) were used as dopants and the structure and morphology of the semiconductor films were studied using IR spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The absorption spectra recorded in the ultraviolet-visible region for the deposited films showed the Q and Soret bands related to the electronic π-π* transitions in M2Pc molecules. Optical characterization of the films indicates electronic transitions characteristic of amorphous thin films with optical bandgaps between 1.2 and 2.4 eV. Finally, glass/ITO/doped M2Pc/Ag thin-film devices were produced and their electrical behavior was evaluated by using the four-tip collinear method. The devices manufactured from Na2Pc have a small rectifying effect, regardless of the organic dopant used, while the device manufactured from Li2Pc-TCNQ presents ohmic-like behavior at low voltages, with an insulating threshold around 19 V. Parameters such as the hole mobility (μ), the concentration of thermally-generated holes (p0), the concentration of traps per unit of energy (P0) and the total trap concentration (Nt(e)) were also determined for the Li2Pc-TTF device.