Query: charge transport in low-temperature processed thin-film

Candidate papers:

abstract: The influence of the composition within multilayered heterostructure oxide semiconductors has a critical impact on the performance of thin film transistor (TFT) devices. The heterostructures, comprising alternating polycrystalline indium oxide and zinc oxide layers, are fabricated by a facile atomic layer deposition (ALD) process, enabling the tuning of its electrical properties by precisely controlling the thickness of the individual layers. This subsequently results in enhanced TFT performance for the optimized stacked architecture after mild thermal annealing at temperatures as low as 200 degC. Superior transistor characteristics, resulting in an average field effect mobility (msat. of 9.3 cm2 V 1 s 1 W/ L 500) an on/off ratio Ion/ Ioff) of 5.3 x 109, and a subthreshold swing of 162 mV dec 1, combined with excellent long term and bias stress stability are thus demonstrated. Moreover, the inherent semiconducting mechanism in such multilayered heterostructures can be conveniently tuned by controlling the thickness of the individual layers. Herein, devices comprising a higher In2O3/ZnO ratio, based on individual layer thicknesses, are predominantly governed by percolation conduction with temperature independent charge carrier mobility. Careful adjustment of the individual oxide layer thicknesses in devices composed of stacked layers plays a vital role in the reduction of trap states, both interfacial and bulk, which consequently deteriorates the overall device performance. The findings enable an improved understanding of the correlation between TFT performance and the respective thin film composition in ALD based heterostructure oxides.
author_names: Jan Krausmann

Shawn Sanctis

Jorg Engstler

Martina Luysberg

Michael Bruns

Jorg J Schneider
title: Charge Transport in Low Temperature Processed Thin Film Transistors Based on Indium Oxide/Zinc Oxide Heterostructures.
venue: ACS applied materials interfaces
year: 2018

abstract: Process structure transport relationships in low temperature processed, blade coated In2O3 transistors using sol gel and combustion chemistries are explored with X ray scattering techniques. Electron mobility of 4.5 cm2 V 1 s 1 is achieved at 220 degC.
author_names: Ahmad R Kirmani

Emily F Roe

Christopher M Stafford

Lee J Richter
title: Role of the electronically active amorphous state in low temperature processed In2O3 thin film transistors
venue: Materials Advances
year: 2020

abstract: Abstract Perovskite solar cells (PSCs) have achieved remarkable power conversion efficiencies (PCEs) owing to their extraordinary optoelectronic properties. Electron transporting layer (ETL) has been proved to have a significant influence on the photovoltaic performance and stability of cell devices. Herein, for the first time, we prepare a low temperature processed compact In2O3 film derived from a highly stable modified indium precursor solution as a promising ETL for stable and efficient air processed PSCs. The addition of acetylacetone as a chelation ligand in the solution effectively inhibits the hydrolysis reactions by chelating In3+ thus contributing to the formation of compact In2O3 film at a low temperature of 200 degC. Dense CH3NH3PbI3 perovskite films with many microns scale grains are fabricated using a scalable doctor blade method under a harsh ambient condition (relative humidity of 40 50% Using the proposed compact In2O3 film as ETL, the electron extraction and charge transport at the ETL/perovskite interface are significantly improved. As a result, the air processed PSC based on compact In2O3 film delivers a champion PCE of 13.97% greatly outperforming the device with a pristine In2O3 film (9.81% In addition to high efficiency, the PSC incorporating proposed compact In2O3 film exhibits an excellent long term stability, maintaining 94% of its initial PCE after stored in air for 31 days. This study demonstrates the feasibility of fabricating stable and efficient air processed PSCs using low temperature processed In2O3 ETL, which is expected to have a positive impact in the manufacturing community of solution processed In2O3 film as well as air processed PSCs.
author_names: Xiaoqing Zhang

Jingling Li

Zhuoneng Bi

Kun He

Xueqing Xu

Xiudi Xiao

Yanqing Zhu

Zhang Yongjun

Zhong Liuwen

Gang Xu

Huangzhong Yu
title: Stable and efficient air processed perovskite solar cells employing low temperature processed compact In2O3 thin films as electron transport materials
year: 2020

abstract: A low temperature solution processed thin film transistor (TFT) using zinc oxide (ZnO) film as an exposed sensing semiconductor channel was fabricated to detect and identify various solution solvents. The TFT devices would offer applications for low cost, rapid and highly compatible water soluble detection and could replace conventional silicon field effect transistors (FETs) as bio sensors. In this work, we demonstrate the utility of the TFT ZnO channel to sense various liquids, such as polar solvents (ethanol) non polar solvents (toluene) and deionized (DI) water, which were dropped and adsorbed onto the channel. It is discussed how different dielectric constants of polar/non polar solvents and DI water were associated with various charge transport properties, demonstrating the main detection mechanisms of the thin film transistor.
author_names: Hsin-Chiang You

Cheng-Jyun Wang
title: Low Temperature, Solution Processed, Transparent Zinc Oxide Based Thin Film Transistors for Sensing Various Solvents
venue: Materials
year: 2017

abstract: Abstract In this experiment, the molybdenum oxide (MoOX) layer were fabricated by spin coated ammonium heptamolybdate (NH4)6Mo7O24 4H2O) solution and thermal annealing treatment. The MoOX layer is shown the deeper energy level, which is more match the highest occupied molecular orbital (HOMO) energy level of the donor. The effect of the thermal annealing of the MoOX layer on hole mobility and photovoltaic performance was investigated. It was found that the 16 nm thick MoOX layer has the best hole mobility and photovoltaic performance as a HEL device. From the space charge limited current (SCLC) and time of flight (TOF) curve, the MoOX layer has shown the better hole extract and transport ability compared with polyethylenedioxy thiophene:polystyrenesulfonate (PEDOT:PSS, Clevios Al4083) layer. The photocurrent density versus effective voltage (Jph Veff) curve, short circuit current (JSC) and open circuit voltage (VOC) value dependent on incident light intensity is confirmed that the weaken charge carrier recombination of MoOX based PSCs at the open circuit condition and short circuit condition. After prolonged light illumination (during ten days) the MoOX based PSCs is shown the better photo stability compared with PEDOT:PSS based PSCs and the similar decrease ratio compared with inverted PSCs.
author_names: Shengli Niu

Simin Xing

Xiangning Zhan

Zhiyong Liu

Ning Wang

Weiliang Zheng
title: Low temperature solution processed molybdenum oxide thin film as ITO modified layer for polymer solar cells
year: 2018

abstract: The recent evolution of solution processed hybrid organic inorganic perovskite based photovoltaic devices opens up the commercial avenue for high throughput roll to roll manufacturing technology. To circumvent the thermal limitations that hinder the use of metal oxide charge transport layers on plastic flexible substrates in such technologies, we employed a relatively low power nitrogen plasma treatment to achieve compact SnO2 thin film electrodes at near room temperature. The perovskite photovoltaic devices thus fabricated using N2 plasma treated SnO2 performed on par with thermally annealed SnO2 electrodes and resulted in a power conversion efficiency (PCE) of ca. 20.3% with stabilized power output (SPO) of ca. 19.1% on rigid substrates. Furthermore, the process is extended to realize flexible perovskite solar cells on indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates with champion PCE of 18.1% (SPO ca. 17.1% which retained ca. 90% of its initial performance after 1000 bending
author_names: Anand S Subbiah

Nripan Mathews

Subodh Gautam Mhaisalkar

Shaibal K Sarkar
title: Novel Plasma Assisted Low Temperature Processed SnO2 Thin Films for Efficient Flexible Perovskite Photovoltaics
year: 2018

abstract: Abstract Na incorporation is widely considered to play an important role in low temperature processed Cu(In,Ga)Se 2 (CIGS) solar cells. In this work, we used post deposition treatment (PDT) method for Na incorporation in CIGS films, which involved the deposition of a thin NaF layer accompanied by thermal annealing. It was found that thermal annealing drove the diffusion of Na into CIGS absorbers without causing loss of elements and change of crystallinity. The dependence of the photovoltaic performance and recombination of CIGS solar cells on the Na PDT temperature was investigated. Impedance spectroscopy and admittance spectroscopy were used to characterize the recombination and defects of CIGS solar cells. The results indicated that the CIGS solar cells with Na PDT exhibited significant improvement of photovoltaic performance compared to those with Na free. The enhanced transport performances of Na treated cells were attributed to the decreased space charge region (SCR) recombination. Both Na free and Na treated at 300 degC CIGS devices showed a donor defect with activation energy of about 295 meV, while the Na treated devices demonstrated lower density of states, which resulted in an improved V oc A maximum conversion efficiency of 11.9% was achieved for CIGS solar cells with Na PDT temperature at 300 degC.
author_names: He Xulin

Jiang Liu

Ye Qinyan

Kun Luo

Yidong Jiang

Cheng Liao

Liangqi Ouyang

Da-ming Zhuang

Jun Mei

Woon-Ming Lau
title: The role of Na incorporation in the low temperature processed CIGS thin film solar cells using post deposition treatment
year: 2016

abstract: Low temperature, solution processed metal oxide thin film transistors (MEOTFTs) have been widely investigated for application in low cost, transparent, and flexible electronics. To enlarge the application area, solution processed gate insulators (GI) have been investigated in recent years. We investigated the effects of the organic/inorganic bi layer GI to ZnO thin film transistors (TFTs) PVP, YO(x) nanoparticle composite, and polysilazane bi layer showed low leakage current 10( 8) A/cm2 in 2 MV) which are applicable in low temperature processed MEOTFTs. Polysilazane was used as an interlayer between ZnO and PVP, YO(x) nanoparticle composite as a good charge transport interface with ZnO. By applying the PVP, YO(x) nanoparticle composite/polysilazane bi layer structure to ZnO TFTs, we successfully suppressed the off current (I(off) to 10( 11) and fabricated good MEOTFTs in 180 degrees C.
author_names: Hyeonwoo Shin

Chan-mo Kang

H Chae

Hyun-Gwan Kim

K H Baek

Hyoung Jin Choi

Mansoo Park

Lee Mi Do

Changhee Lee
title: A Low Temperature, Solution Processed Poly(4 vinylphenol) YO(x) Nanoparticle Composite/Polysilazane Bi Layer Gate Insulator for ZnO Thin Film Transistor.
venue: Journal of nanoscience and nanotechnology
year: 2016

abstract: Inspired by the silicide technology in manufacturing silicon devices and the ongoing lack of knowledge on post metallization annealing in realizing oxide devices, we investigated post contact annealing for solution processed InGaZnO transistors. Low temperature annealing in air is found to significantly improve device uniformity, reproducibility, and subthreshold charge transport. However, this method is highly dependent on the employed contact metal. Detailed examination of devices using Al, Au, and Cu reveals that the physics of a metal/semiconductor interface is vital to its post anneal response, which results in distinct device characteristics. Our results provide clues to better understand oxide transistors and to optimize their performance.
author_names: Yong Xu

Chuan Liu

Paul S K Amegadze

Won-Tae Park

Dang Xuan Long

Takeo Minari

Francis Balestra

Gerard Ghibaudo

Yong-Young Noh
title: Significant roles of low temperature post metallization annealing in solution processed oxide thin film transistors
year: 2014

abstract: We have investigated the reversal of conductivity of solution processed ZnSnO (ZTO) films and thin film transistors (TFTs) under high pressure annealing (HPA) in terms of the field effect mobility. When the ZTO TFTs had Zn Sn ratios of 1 1 and 2 1 under HPA, the value of the field effect mobility showed a reversal phenomenon compared to TFTs without HPA. This result was attributed to the increase in conductivity due to the Fermi level being shifted up near the conduction band minimum by Sn activation under HPA. Furthermore, strong hybridization of the Sn 5s and the oxygen 2p orbitals was induced by HPA. As a result, HPA could contribute to the orbital splitting related to electron transport in the conduction band. In addition, the reliability of the HPA ZTO TFT was more stable than without HPA because of the reduction in interface charge traps.
author_names: You Seung Rim

Byung Du Ahn

J W Park

Hongmin Kim
title: Manifestation of reversal conductivity on high pressurizing of solution processed ZnSnO thin film transistors at low temperature
year: 2014