High-Performance Zinc Tin Oxide Semiconductor Grown by Atmospheric-Pressure Mist-CVD and the Associated Thin-Film Transistor Properties

Abstract

Zinc tin oxide (Zn-Sn-O, or ZTO) semiconductor layers were synthesized based on solution processes, of which one type involves the conventional spin coating method and the other is grown by mist chemical vapor deposition (mist-CVD). Liquid precursor solutions are used in each case, with tin chloride and zinc chloride (1:1) as solutes in solvent mixtures of acetone and deionized water. Mist-CVD ZTO films are mostly polycrystalline, while those synthesized by spin-coating are amorphous. Thin-film transistors based on mist-CVD ZTO active layers exhibit excellent electron transport properties with a saturation mobility of 14.6 cm/(V s), which is superior to that of their spin-coated counterparts (6.88 cm/(V s)). X-ray photoelectron spectroscopy (XPS) analyses suggest that the mist-CVD ZTO films contain relatively small amounts of oxygen vacancies and, hence, lower free-carrier concentrations. The enhanced electron mobility of mist-CVD ZTO is therefore anticipated to be associated with the electronic band structure, which is examined by X-ray absorption near-edge structure (XANES) analyses, rather than the density of electron carriers.

The effect of small addition of copper on the growth process, structure, surface charge and adsorption properties of ZnO films in the pyrolysis of dithiocarbamates

“…35,36 This approach has also been used by a number of other teams. [37][38][39][40] The advantage of this approach is its versatility: the DTC forms complexes with a large number of different metals 41 which have similar decomposition temperatures. This enables obtaining single and multicomponent films of different compositions with different levels of doping with the specified components 42,43 while using one basic organic ligand (DTC).…”

Development and characterization of (Zn,Sn)O thin films for photovoltaic application as buffer layers

“…However, due to environmental risks associated with using toxic cadmium (Cd) and it's relatively low band gap (2.4 eV) [1], many research efforts were focused on the replacement of CdS with new Cd-free materials that fulfill the requirements for a non-toxic and effective buffer layer [2]. Recently, a class of thin-film metal oxide semiconductors characterized by high optical transparency and a good electrical conductivity had been applied in several optoelectronic fields: thin film transistors (TFT) [3], gas sensors [4] and buffer layers in many solar cells, such as CIGS (18.2%) [5], CZTS (12.6%) [6] and CZTSSe (8.6%) [7]. Known as one of the transparent conductive oxides (TCOs) (Zn,Sn)O or ZTO had demonstrated its ability to be a promising alternative as a buffer layer in thin-film solar cell technology as well as a transparent material for bifacial solar cells [8].…”

Improved Interface Charge Extraction by Double Electron Transport Layers for High‐Efficient Planar Perovskite Solar Cells

“…ZTO exhibits environmental nontoxicity, high thermal stability, wide bandgap, high transmittance, controllable electrical performances, and high electron mobility (10À15 cm 2 V À1 S À1 ). [31,32] Sha et al reported the PCE of 17.21% for mesoporous ZTO layerbased PSCs. [33] Wu et al fabricated PSCs by applying ZTO as ETL with a PCE of 16.0%, which is much lower than the best PCE reported so far.…”

“…As a multifunctional n‐type semiconductor, ZTO is another promising metal oxide with excellent optical and electronic properties, which has been widely used in many fields, such as transistors, solar cells, and Li‐ion batteries. ZTO exhibits environmental nontoxicity, high thermal stability, wide bandgap, high transmittance, controllable electrical performances, and high electron mobility (10−15 cm 2 V −1 S −1 ) . Sha et al reported the PCE of 17.21% for mesoporous ZTO layer‐based PSCs .…”