Among them, HfO x is a superior resistive switching material, which has stable electrical properties, good process repeatability, and small leakage current [23,24].
However, due to the scarcity of the element indium in the earth and consequently the soaring prices, recently, nanomaterials, such as carbon nanotubes (CNTs) [5], graphene [6], metal grids [7], and metallic nanowires [8], have attracted great attention as candidates of TCL due to their unique electrical properties, good transparency, and mechanical flexibility.
Nanocomposite films consisting of GO nanosheets and CPs have recently generated interest as materials for bioapplications, such as cell scaffolding or chemical sensing, as a result of their favorable electrical properties, good stability, neuronal biocompatibility, and ease of surface modification with bioactive molecules.
Poly (3,4-ethylenedioxythiophene) polystyrene sulphonate (PEDOT PSS) is the most widely used hole transporting layer (HTL) in planar perovskite solar cells, which shows excellent optical, electrical properties and good compatibility with low temperature, solution and flexible processing.
Polyaniline (PANI) is one of the conducting polymers that has been extensively studied due to its extraordinary electrical properties and good environmental stability [119].
II VI nanostructure semiconductors have been of considerable interest in the past decade due to their unique optical and electrical properties, and good candidates for the building blocks of functional Nano devices such as field-effect transistors (FETs), [26, 27] photo detectors (PDs), [28, 29] light-emitting diodes (LEDs), [30] photovoltaic (PV) devices [31, 32] and logic circuits [33, 34].
Spinel ferrite NPs with the general formula MFe2O4 (where M is A is divalent cation of Zn, Ni, Mn, Mg or Co) are very important materials because of their interesting magnetic and electrical properties with good chemical and thermal stabilities [ 5].
Beside the good electrical properties, CNTs have also a good stability in time, due to their higher corrosion resistance with respect to Pt electrodes, allowing the CNTs-based CE to maintain unaltered properties of DSSC device for longer periods of time.
For flexible TE materials that can be used over 500 K, carbon nanotubes (CNTs) are a promising candidate because of their large Seebeck coefficient as exhibited in CNT films in addition to their superior electrical properties, chemical stability, good mechanical strength with excellent flexibility, and thermo-oxidative stability up to 873 K [11 13].
CNTs have also been embedded into polymers to fabricate composites with good electrical properties, including dielectric constants with higher values and good thermal stability [2].
In addition, the 'electron crystal' behavior is well maintained to achieve good electrical properties because alloying Te at Se sites scarcely affect the bottom of conduction band.
