Nucleobases thin films deposited on nanostructured transparent conductive electrodes for optoelectronic applications

Abstract

Environmentally-friendly bio-organic materials have become the centre of recent developments in organic electronics, while a suitable interfacial modification is a prerequisite for future applications. In the context of researches on low cost and biodegradable resource for optoelectronics applications, the influence of a 2D nanostructured transparent conductive electrode on the morphological, structural, optical and electrical properties of nucleobases (adenine, guanine, cytosine, thymine and uracil) thin films obtained by thermal evaporation was analysed. The 2D array of nanostructures has been developed in a polymeric layer on glass substrate using a high throughput and low cost technique, UV-Nanoimprint Lithography. The indium tin oxide electrode was grown on both nanostructured and flat substrate and the properties of the heterostructures built on these two types of electrodes were analysed by comparison. We report that the organic-electrode interface modification by nano-patterning affects both the optical (transmission and emission) properties by multiple reflections on the walls of nanostructures and the electrical properties by the effect on the organic/electrode contact area and charge carrier pathway through electrodes. These results encourage the potential application of the nucleobases thin films deposited on nanostructured conductive electrode in green optoelectronic devices.

Electronically Tunable Transparent Conductive Thin Films for Scalable Integration of 2D Materials with Passive 2D–3D Interfaces

“…Furthermore, the deposition process for scalable fabrication of nc-C/AlO x heterostructures is expected to be broadly compatible with diverse substrates and suitable for applications in numerous optoelectronic applications, extending beyond 2D materials. [46,47]…”

Pulsed Laser Deposition of Transparent Conductive Oxides on UV-NIL Patterned Substrates for Optoelectronic Applications

“…Compared with the structure prepared on ITO/glass electrode, the shape of the I-V characteristic of the structure deposited on ITO/NP-glass electrode was changed into a very close rectifying diode behavior. At small voltage, a slow increase in the current value is noted at the same time with the voltage increase, while a faster increase in the current is obtained after 0.5 V probably due to the growth of the number of electrons that cross the barrier and are more easily collected to the patterned electrode [103].…”

“…Hence, in the case of adenine deposited on ITO/glass substrate, the I-V characteristic (recorded in dark between −1 V and 1 V applied voltage) is changed from linear (at small voltage) to nonlinear at higher voltage (>0.5 V) probably due to the different properties shown by the contacts ITO/adenine and adenine/Al [103]. Regarding the electrode patterning, it is expected that this effect induces some changes in the electrical properties of the investigated structures by modifying the electrical field, which in turn can affect the charge carrier transport and their collection [104].…”

“…The TCO films (ITO and AZO) deposited by PLD on flat and nanopatterned glass substrates were used for developing organic heterostructures for optoelectronic applications. Schematic representation of two organic heterostructures and their I-V characteristics are given in Figure 10: one based on adenine (Ade), the nucleic acid base film being deposited on ITO by vacuum thermal evaporation [103], and another based on N,N′-di(1-naftalenil)-N,N′-diafenil-(1,1′-bifenil)-4,4′-diamina (α-NPD), 1,4-bis [4-(N,N-diphenylamino)phenylvinyl] benzene (P78) and 4,7 diphenyl-1,10-phenanthroline (BPhen), the three stacked organic films being deposited on AZO by matrix-assisted pulsed laser evaporation (MAPLE) [86]. For both organic structures, aluminum electrode (100 nm) was deposited by vacuum thermal evaporation.…”

Effect of Aluminum Nanostructured Electrode on the Properties of Bulk Heterojunction Based Heterostructures for Electronics

“…Previous investigations have highlighted how nano-patterning affects the properties of aluminum (Al) layers [ 42 ]. The effect of periodic patterned micro/nanostructures developed on the metal surface, at the interface electrode/organic semiconductor on the properties of small molecule organic bi-layer heterostructures [ 43 ], bulk-heterojunction-based organic heterostructures [ 44 ], organic photovoltaic devices [ 45 ] and nucleobase thin films for optoelectronic applications [ 46 ] has also been investigated.…”