Influence of interface roughness on the performance of nanoparticulate zinc oxide field-effect transistors

Abstract

Nanoparticulate zinc oxide is regarded as one of the most promising inorganic materials for printable field-effect transistors (FETs), which work in the n-channel enhancement mode, due to the compatibility with solution, low-temperature, and high throughput processes. Since nanoparticulate films are composed of the nanoparticles and their agglomerates, the roughness of the interface to the insulating layer, where the channel of the FETs is formed, is a critical issue. Thus, the influence of the interface roughness on the field-effect mobility of the FETs is investigated in conjunction with film roughness and capacitance analyses. The field-effect mobility increases almost by a factor of 50, from 2.0×10−4 to 8.4×10−3 cm2 V−1 s−1, even if the reduction in the average roughness of the films is as small as 1.7 nm.

Electrochemically-Gated Field-Effect Transistor with Indium Tin Oxide Nanoparticles as Active Layer

“…It is worthwhile to compare the difference between dielectric gating and electrochemical gating for the case of printable nanoparticulate structures. For a nanoparticle channel field-effect device with dielectric gating it is a prerequisite to have a quality interface between the dielectric and nanoparticles to ensure sufficient gating efficiency [13]. Therefore, a quality dispersion of nanoparticles with low agglomerate size is required.…”

Metal oxide semiconductor thin-film transistors for flexible electronics

“…Furthermore, high film porosity and roughness at the interface semiconductor/gate dielectrics have been demonstrated to be detrimental for the TFT performance. 190,238 The impact of residual ligands, grain boundaries, as well as interfacial roughness generally limit the carrier mobility of flexible n-type solution-processed metal oxide semiconductor NP TFTs in approach (A) to below 1 cm 2 . 76,227 Nevertheless, difficulties of alignment and accurate placement of the NWs with respect to the source/drain electrodes are a drawback for more widespread applications.…”

“…In general, two approaches can be used to solution-deposit metal oxide semiconducting materials: 236 (A) The material is first synthesized and tailored into nanoparticles, nanorods, or nanowires. 76,190,226,227,230,231,238 These nano-scaled shapes are then dispersed in suitable solvents and subsequently deposited and dried. (B) Alternatively, the precursor solution is first deposited and then converted to the final metal oxide semiconducting material, most commonly via thermal annealing at temperatures in the range of 200 to 500 C, or alternatively via UV irradiation.…”

Improved bias stress stability of In–Ga–Zn–O thin film transistors by UV–ozone treatments of channel/dielectric interfaces

“…[4,15,16]. Improvements in the μ FE with longer UV irradiation as shown in Table 1 seem to be the result of the modification of the channel/dielectric interface that decreased the density of interface traps.…”