**5. Applications of solution-processed functional oxides for TFTs and display**

#### **5.1. Low-temperature all solution-derived amorphous oxide TFTs**

TFTs, in which all the layers were fabricated using simple chemical solution-processed, vacuum-free routes, followed by thermal annealing at 400°C, were demonstrated [34]. A ruthenium oxide (RuO<sup>2</sup> ) was used for both gate and source/drain electrodes. Amorphous LZO and zirconium-indium-zinc oxide (ZIZO) films were used as the gate insulator and channel layer, respectively, which enabled the fabrication of a TFT with the desired performance at a sufficiently low temperature. Transfer characteristics of the low-temperature all solutionprocessed TFT are shown in **Figure 10**. The obtained "on/off" ratio, *SS*-factor, and *μ* were ∼6 × 10<sup>5</sup> , 250 mV/decade, and 5.80 cm<sup>2</sup> V−1 s−1, respectively.

Low-Temperature Solution-Processable Functional Oxide Materials for Printed Electronics http://dx.doi.org/10.5772/intechopen.75610 93

**Figure 10.** Transfer curves of low-temperature all solution-processed oxide TFT.

**Material Method T (°C) ρ/σ μ (cm2 V−1 s−1) Eg**

CuCrO<sup>2</sup>

92 Green Electronics

CuCrO<sup>2</sup>

Ca<sup>3</sup> Co<sup>4</sup>

Y:CuAlO<sup>2</sup> Li:ZnO

talline bulk Bi<sup>3</sup>

given in **Table 5**.

nium oxide (RuO<sup>2</sup>

**display**

∼6 × 10<sup>5</sup>

Ru<sup>3</sup>

Electrohydrodynamic

Ln-M-O (M = Ru, Ir, and Ln is a lanthanide)

A-B-O (A = Bi, Pb; B = Ru, Ir)

CuAlO<sup>2</sup> So-gel 900 250 Ω cm — — 2002 [92]

CuFeO<sup>2</sup> So-gel 700 0.36 S cm−1 0.7 3.05 2012 [97]

, CuAl0.5Cr0.5O2 Sol-gel 600 11–16 Ω cm — — 2009 [96]

:Mg CSD 600 0.31 Ω cm 0.7 2012 [98]

O9 CSD 650 57 mΩ cm — — 2014 [92] CuCrO<sup>2</sup> Combustion 180 0.14 S cm−1 0.23 3.0 2018 [99] CuCrO<sup>2</sup> Spray pyrolysis 345 12 S cm−1 6.4 × 10−3 2.4 2015 [100]

temperatures [95]. The lowest necessary temperatures for a-BiRuO, a-PbRuO, and a-BiIrO were 240, 290, and 350°C, respectively, resulting in RT DC resistivities of 3.8, 1.7, and 3.8 mΩ cm, respectively. The resistivity of a-BiRuO film has nearly reached the value of crys-

p-type oxides, the low-resistivity values of these amorphous oxides are matched only by epitaxial LaCuOSe:Mg annealed at a high temperature of 1000°C (1.1 mΩ cm). A summary of electro-optical characteristics of some solution-processed p-type conductive oxides is

**5. Applications of solution-processed functional oxides for TFTs and** 

TFTs, in which all the layers were fabricated using simple chemical solution-processed, vacuum-free routes, followed by thermal annealing at 400°C, were demonstrated [34]. A ruthe-

and zirconium-indium-zinc oxide (ZIZO) films were used as the gate insulator and channel layer, respectively, which enabled the fabrication of a TFT with the desired performance at a sufficiently low temperature. Transfer characteristics of the low-temperature all solutionprocessed TFT are shown in **Figure 10**. The obtained "on/off" ratio, *SS*-factor, and *μ* were

**5.1. Low-temperature all solution-derived amorphous oxide TFTs**

, 250 mV/decade, and 5.80 cm<sup>2</sup> V−1 s−1, respectively.

580 Ω cm 15.06 Ω cm

1100 500

**Table 5.** Electro-optical characteristics of some solution-processed p-type conductive oxides.

CSD <400 10−3–10−2 Ω cm — — 2012 [93]

CSD 240 1.3–3.8 mΩ cm — 0.2 2012 [95]

O11 (1.4 mΩ cm), which suggests that the films are of high quality. In

) was used for both gate and source/drain electrodes. Amorphous LZO

– 0.918 **(eV)**

– – 2015 [101]

**Ref.**
