Article
Engineering, Electrical & Electronic
Po-Hsun Chen, Hong-Chih Chen, Chuan-Wei Kuo, Jian-Jie Chen, Hui-Chun Huang
Summary: This study introduces a UV photo detector based on a dual-active-layer a-IGZO thin-film transistor, with a Zn-rich IGZO layer serving as a charge trapping center. The electron injection closer to the drain end under a drain bias of 10V causes a significant resistance effect in the active layer, evident in the unilateral C-V measurement. The UV light induces holes close to the electron injection location in the Zn-rich bulk, resulting in barrier lowering effects and additional photocurrent generation.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Zhi-Yue Li, Shu-Mei Song, Wan-Xia Wang, Jian-Hong Gong, Yang Tong, Ming-Jiang Dai, Song-Sheng Lin, Tian-Lin Yang, Hui Sun
Summary: In this study, homojunction thin-film transistors (TFTs) with amorphous indium gallium zinc oxide (a-IGZO) as active channel layers were fabricated by RF magnetron sputtering. The effect of oxygen partial pressure on the properties of IGZO thin films was investigated. It was found that the resistivity of IGZO thin films increases with higher oxygen partial pressure. Optimal electrical characteristics were observed in homojunction IGZO TFTs with an oxygen partial pressure of 1.96%.
Review
Materials Science, Multidisciplinary
Bojing Lu, Fei Zhuge, Yi Zhao, Yu-Jia Zeng, Liqiang Zhang, Jingyun Huang, Zhizhen Ye, Jianguo Lu
Summary: This review provides a comprehensive overview of In-free amorphous oxide semiconductors (AOSs), including their fundamental properties and practical applications. Various types of In-free AOSs, with a focus on ZnSnO-based AOSs, are introduced. The study also investigates In-free AOS-based thin-film transistors (TFTs), which are crucial for next-generation transparent and flexible displays. Additionally, the review discusses the applications of In-free AOSs in transparent electrodes, sensors, memristors, synaptic devices, and circuits.
CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Taebin Lim, Suhui Lee, Jiseob Lee, HyungJin Choi, Byunglib Jung, SeungHyub Baek, Jin Jang
Summary: Artificial synapses are an essential element in neuromorphic computing systems. This study presents the development of a coplanar synaptic thin-film transistor using crystalline indium gallium tin oxide. The device demonstrates important biological synaptic behaviors and utilizes a new mechanism involving positively charged oxygen vacancies. Unlike previous reports, this device allows for the use of conventional gate insulators, making it a suitable candidate for highly integrated neuromorphic chips.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Won-Gi Kim, Young Jun Tak, Hyukjoon Yoo, Hyung Tae Kim, Jeong Woo Park, Dong Hyun Choi, Hyun Jae Kim
Summary: By using sodium hypochlorite (NaClO) solution as an activation source, the activation temperature of a-IGZO TFTs was reduced from 300 to 150 degrees C, leading to satisfactory electrical characteristics. The mechanism of NaClO activation for a-IGZO TFTs involves photo-assisted oxygen radical (POR) and heat-driven oxygen radical (HOR) effects, which generate reactive oxygen species to activate TFTs at low temperatures.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Xianyang Xue, Tingting Zhao, Xueming Tian, Li Yuan, Zhigan Wang, Tongkuai Li, Jianhua Zhang
Summary: This article proposes a flexible dual-parameter sensor array based on a-IGZO TFTs, which decouples pressure and temperature perception by optimizing the combination of MXene and carbon nanotubes hybrid films. It has potential applications in the field of multifunctional electronic skin.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Nanoscience & Nanotechnology
Jiaona Zhang, Weihong Huang, Kuan-Chang Chang, Yuhao Shi, Changbin Zhao, Xinwei Wang, Hong Meng, Shengdong Zhang, Min Zhang
Summary: The study proposes a low-temperature posttreatment method using supercritical CO2 fluid with a dehydration function to improve the performance of flexible a-IGZO TFTs. After treatment, the TFT shows significant improvement in drivability, subthreshold swing, threshold voltage, and I-on/I-off ratio. The posttreated TFTs also exhibit good uniformity and reproducibility, with performance remaining stable even after repeated bending.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Electrical & Electronic
Maria Isabel Pintor-Monroy, Martin Gregorio Reyes-Banda, Carlos Avila-Avendano, Manuel A. Quevedo-Lopez
Summary: In this study, a simple and cost-effective method for fabricating thin film transistors (TFTs) based on undoped amorphous Ga2O3 thin films deposited at room temperature by magnetron sputtering is discussed. The control of Ga2O3 thin film resistivity over a wide range is demonstrated by controlling the deposition power and pressure. These TFTs exhibit promising characteristics and have been evaluated as phototransistors under DUV radiation, showing high rejection ratio, responsivity, gain, detectivity, and photosensitivity.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Kaizhen Han, Subhranu Samanta, Shengqiang Xu, Ying Wu, Xiao Gong
Summary: The study found that by reducing the equivalent oxide thickness, a temperature-independent mu(eff) can be achieved in the high field or high carrier concentration regime, while a strong temperature dependency is observed in the low field or low carrier concentration regime. Additionally, the relationship between EOT scaling and the gate bias voltage at which E-F equals to E-M was studied, revealing that α-IGZO TFTs can achieve high performance in low-power applications.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Nanoscience & Nanotechnology
Huan Yang, Xiaoliang Zhou, Haishi Fu, Baozhu Chang, Yuxin Min, Hao Peng, Lei Lu, Shengdong Zhang
Summary: The doping effect induced by aluminum treatment can improve the performance and stability of SATG a-IGZO TFTs by enhancing the conductivity of the source-drain regions. The generated oxygen vacancies and metal interstitials play a crucial role in the doping process. The results of the study demonstrate that this doping effect originates from the bulk rather than surface treatment.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Review
Materials Science, Multidisciplinary
Himani Arora, Artur Erbe
Summary: The field of two-dimensional materials, particularly III-VI monochalcogenides like indium selenide and gallium selenide, has attracted significant interest due to their high intrinsic mobility and direct bandgap properties. However, their sensitivity to environmental influences and limited scalable synthesis methods have hindered their practical applications. Research has focused on improving device structures and developing effective encapsulation techniques to prevent degradation.
Article
Chemistry, Multidisciplinary
Jaehyun Kim, Joon Bee Park, Ding Zheng, Joon-Seok Kim, Yuhua Cheng, Sung Kyu Park, Wei Huang, Tobin J. Marks, Antonio Facchetti
Summary: A new strategy was reported to achieve high-performance solution-processed metal oxide thin-film transistors by introducing metallic micro-island array on top of the metal oxide back channel. Al-MIA IGZO TFTs exhibited superior performance compared to controls, with high electron mobility and broad applicability.
ADVANCED MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Guangan Yang, Hao Tian, Zuoxu Yu, Tingrui Huang, Yong Xu, Huabin Sun, Weifeng Sun, Wangran Wu
Summary: This work demonstrates 400-V amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with a drift region doped by hydrogen near the drain side. By optimizing the length of the drift region and the hydrogen flow rate, the breakdown voltage and output current are improved, along with enhanced carrier concentration. The proposed 400-V a-IGZO TFTs exhibit an excellent tradeoff relationship between on-resistance and breakdown voltage.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Mingyuan Liu, Hyeonghun Kim, Xingyu Wang, Han Wook Song, Kwangsoo No, Sunghwan Lee
Summary: The introduction of a conducting IZO buffer has successfully reduced the energy barrier for charge carriers and specific contact resistance, leading to an enhanced field effect mobility in amorphous IZO thin-film transistors.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Subhranu Samanta, Kaizhen Han, Chen Sun, Chengkuan Wang, Annie Kumar, Aaron Voon-Yew Thean, Xiao Gong
Summary: The study found that in the sub-10-nm regime, TFT devices with a channel thickness of 3.6 nm can achieve low subthreshold swing and the highest effective mobility. The effective mobility does not degrade significantly as the alpha-IGZO thickness is reduced from 6 to 3.6 nm.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Chemistry, Multidisciplinary
Lulu Sun, Mengyuan Yang, Xinyun Dong, Lu Hu, Lin Hu, Cong Xie, Tiefeng Liu, Fei Qin, Wen Wang, Youyu Jiang, Mengying Wu, Wei Cao, Felipe A. Larrain, Canek Fuentes-Hernandez, Ke Meng, Bernard Kippelen, Peter Mueller-Buschbaum, Yinhua Zhou
Summary: A novel method called orthogonal liquid-liquid-contact (OLLC) doping has been developed for the preparation of electrically doped films, which enables efficient doping at the interface of water and an organic solvent during film formation. This technique offers the advantages of ease of operation and high efficiency, making it suitable for devices such as organic photovoltaics and light-emitting diodes.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Physics, Applied
Gunhee Kim, Canek Fuentes-Hernandez, Sangmoo Choi, Xiaojia Jia, Bernard Kippelen
Summary: This study presents a method for extracting the intrinsic contact resistance from organic thin-film transistors (OTFTs), which can be applied to devices with different geometries. The research shows that the intrinsic contact resistance decreases as the gate capacitance density increases.
APPLIED PHYSICS LETTERS
(2021)
Article
Multidisciplinary Sciences
Youngrak Park, Canek Fuentes-Hernandez, Kyungjin Kim, Wen-Fang Chou, Felipe A. Larrain, Samuel Graham, Olivier N. Pierron, Bernard Kippelen
Summary: This study has developed a skin-like elastomeric bulk heterojunction (e-BHJ) photoactive layer with a Young's modulus comparable to human tissues and a high strain at break of 189%. Elastomeric organic photodiodes based on this e-BHJ photoactive layer exhibit low electronic noise currents in the tens of femtoamperes range and noise equivalent power values in the tens of picowatts range under at least 60% strain.
Article
Chemistry, Physical
Matthew W. Cooper, Xiaoqing Zhang, Yadong Zhang, Ajith Ashokan, Canek Fuentes-Hernandez, Seyhan Salman, Bernard Kippelen, Stephen Barlow, Seth R. Marder
Summary: This study compares the properties of carbazole-substituted 2-methyl-5-phenyl-1,3,4-oxadiazoles to their 2,5-diphenyl analogues. The fluorescence of the former compounds is blue-shifted relative to the latter, while similar estimates of the singlet-triplet energy separation are maintained. Additionally, the 2-methyl derivatives show higher reverse intersystem crossing rates and improved efficiency rolloff at high current densities in organic light-emitting diodes.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Physical
Farzaneh Saeedifard, Yi-Chien Chang, Bernard Kippelen, Seth R. Marder, Stephen Barlow
Summary: Insoluble electrically n-doped fullerene-containing films were obtained by thermal annealing, and the covalent tethering and electrical doping reactions were studied. Thermal insolubilization process reduced the electrical conductivity of the films and immobilized the dopant, limiting its diffusion into adjacent layers.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Engineering, Environmental
Minwoo Nam, Youngrak Park, Chihyung Lee, Gunhee Kim, Felipe A. Larrain, Canek Fuente-Hernandez, Doo-Hyun Ko, Bernard Kippelen
Summary: The commercial viability of organic photovoltaics (OPVs) can be improved by simplifying device geometry and fabrication complexity. By using solution-based p-type electrical doping, efficient single-layer OPVs can be realized. Post-process immersion in a 12-molybdophosphoric acid hydrate (PMA) solution reduces trap density and charge recombination without changing the BHJ morphology, enabling the fabrication of high-performance single-layer OPVs with economic top electrode metals.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Organic
Farzaneh Saeedifard, Yasir Naeem, Yannick T. Boni, Yi-Chien Chang, Junxiang Zhang, Yadong Zhang, Bernard Kippelen, Stephen Barlow, Huw M. L. Davies, Seth R. Marder
Summary: Hole-transport materials based on triarylamine derivatives have critical applications in organic electronics. This study demonstrates a method using Rh-carbenoid chemistry to incorporate carboxylic esters and norbornene functional groups into triarylamine materials. The resulting materials exhibit similar properties to those synthesized by conventional means and offer the potential for diverse hole-transport materials with different functional groups.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Physics, Applied
Yi-Chien Chang, Felipe A. Larrain, Canek Fuentes-Hernandez, Youngrak Park, Bernard Kippelen
Summary: We report the application of solution-based p-type electrical doping using 12-molybdophosphoric acid hydrate (PMA) to fabricate organic tandem solar cells. This doping approach allows embedding the hole-collecting component in the photoactive layer, simplifying the device architecture. The charge recombination stack comprising a PMA-doped bottom layer and a trilayer of Ag/AZO/PEIE is compatible with solution-processed top layer.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Organic
Farzaneh Saeedifard, Yasir Naeem, Yannick T. Boni, Yi-Chien Chang, Junxiang Zhang, Yadong Zhang, Bernard Kippelen, Stephen Barlow, Huw M. L. Davies, Seth R. Marder
Summary: Hole-transport materials (HTMs) based on triarylamine derivatives are important in organic electronic applications. This study presents a method to incorporate carboxylic esters and norbornene functional groups into sp2 C-H bonds of triarylamine materials using Rh-carbenoid chemistry. The resulting materials exhibit similar properties to those synthesized by conventional means and offer a straightforward approach to diverse HTMs with different functional groups.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Silja Abraham, Canek Fuentes-Hernandez, Sharmistha Mukhopadhyay, Kumar Singh, Hyung Nun Kim, Oliver Moreno, Claire M. M. Tran, Dharam Raj Kumar, John C. C. Stooksbury, Surya R. R. Kalidindi, Nolan E. E. Hertel, Michel P. P. Shannon, Bernard Kippelen
Summary: Cross-linked polyvinyltoluene (PVT) based plastic scintillators loaded with dyes exhibiting thermally activated delayed fluorescence (TADF) and various amounts of (caproate)di-(methacrylate) bismuth (CMB) were developed. The results of this study show that the cross-linking approach and the use of TADF dyes yield scintillators with good mechanical properties, but the addition of CMB reduces the light yield in gamma spectroscopy experiments.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Engineering, Electrical & Electronic
Dingtian Zhang, Canek Fuentes-Hernandez, Raaghesh Vijayan, Yang Zhang, Yunzhi Li, Jung Wook Park, Yiyang Wang, Yuhui Zhao, Nivedita Arora, Ali Mirzazadeh, Youngwook Do, Tingyu Cheng, Saiganesh Swaminathan, Thad Starner, Trisha L. Andrew, Gregory D. Abowd
Summary: In this research, we introduce in-sensor analog computation to overcome the limitations of conventional vision-based systems. A computational photodetector is developed to extract mid-level vision features and measure them using a wireless system. This technology can be applied in various applications, ranging from explicit surface interactions to implicit activity detection.
NPJ FLEXIBLE ELECTRONICS
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Canek Fuentes-Hernandez, Wen-Fang Chou, Victor A. Rodriguez-Toro, Youngrak Park, Yi-Chien Chang, Felipe A. Larrain, Bernard Kippelen
Summary: An improved characterization of organic photodiode performance allows for a reassessment of electronic noise and optimization of large-area organic photodetectors, which perform comparably to low-noise silicon photodiodes in all metrics except response time at visible wavelengths.
2021 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2021)
Article
Chemistry, Physical
Marie-Helene Tremblay, Kelly Schutt, Federico Pulvirenti, Thorsten Schultz, Berthold Wegner, Xiaojia Jia, Yadong Zhang, Elena Longhi, Raghunath R. Dasari, Canek Fuentes-Hernandez, Bernard Kippelen, Norbert Koch, Henry J. Snaith, Stephen Barlow, Seth R. Marder
Summary: A new polymer CL has been synthesized as a crosslinking additive, which can enhance the electrical conductivity and stability of perovskite solar cells. Devices with undoped PCBCB:CL extraction layers exhibited higher power conversion efficiencies and excellent thermal stability compared to PCBM and PCBCB counterparts.
JOURNAL OF MATERIALS CHEMISTRY A
(2021)
