Article
Engineering, Electrical & Electronic
Xiaoliang Zhou, Yunkai Cao, Jiye Li, Huan Yang, Wengao Pan, Lei Lu, Shengdong Zhang
Summary: This study investigates the direct-current reactive sputtering of aluminum oxide films as a preferable passivation layer for self-aligned top-gate amorphous metal oxide semiconductor thin-film transistors. The grown AlOx films exhibit excellent electrical characteristics and, when combined with a PECVD SiO2 interlayer, provide trustworthy environmental and electrical stability for SATG a-IGZO TFTs.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Chemistry, Physical
Yuhang Guan, Yuqing Zhang, Jinxiong Li, Jiye Li, Yuhan Zhang, Zhenhui Wang, Yuancan Ding, Mansun Chan, Xinwei Wang, Lei Lu, Shengdong Zhang
Summary: In recent years, high-k gate dielectrics have received increasing attention in amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) due to the need for stronger gate controllability. This study developed an ultra-thin top-gate insulator of atomic-layer-deposited (ALD) HfOx for amorphous indium-gallium-zinc oxide (a-IGZO) TFTs. However, the reliability of the 4-nm HfOx-gated a-IGZO transistor is poor due to interface defects caused by the interface reaction between HfOx and a-IGZO during the ALD process. To improve stability, the a-IGZO channel is pre-treated with strong oxidizing plasma. However, further reducing HfOx thickness increases gate leakage current.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Hyunjin Kim, Seohyun Maeng, Soobin Lee, Jaekyun Kim
Summary: Solution-processed IGTO thin film transistors show promising performance in display applications, with higher Sn composition leading to better stability and lower threshold voltage shifts. Tailoring the metal cation composition in IGTO thin films can improve the characteristics of IGTO semiconducting channel systems for low-cost switching devices.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Ziyuan Wang, Sang-Hwa Jeon, Yu-Jin Hwang, Sin-Hyung Lee, Jaewon Jang, In Man Kang, Do-Kyung Kim, Jin-Hyuk Bae
Summary: ZTO TFTs with an Sn/(Sn+Zn) ratio of 0.4 exhibit the highest saturation mobility, lowest subthreshold swing and hysteresis, as well as outstanding positive bias stability, while the negative bias stress-induced instability gradually increases with the proportion of tin due to the ionization of oxygen vacancies. These results will aid in optimizing the composition ratio in rare-metal-free oxide semiconductors for next-generation low-cost electronics.
Article
Engineering, Electrical & Electronic
Jeongho Lee, Jidong Jin, Seohyun Maeng, Gisang Choi, Hayoung Kim, Jaekyun Kim
Summary: This study investigates the performance of indium tin zinc oxide (ITZO) thin-film transistors (TFTs) with different channel structures. The results show that bilayer-channel ITZO TFTs exhibit enhanced electrical performance and bias stress stability compared to single-channel ITZO TFTs. The electrical properties of the bilayer-channel films can be fine-tuned by adjusting their oxygen stoichiometry using an oxygen-compensated capping layer.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Zhenyuan Xiao, Jidong Jin, Jeongho Lee, Gisang Choi, Xiaoyu Lin, Jiawei Zhang, Jaekyun Kim
Summary: This study investigates the effects of an oxygen-compensated capping layer (CCL) on the electrical performance and stability of indium-tin-zinc-oxide (ITZO) thin-film transistors (TFTs). The results show that the oxygen CCL significantly improves the electrical properties and stability of dual-channel ITZO TFTs under different stress modes.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Wanyu Zeng, Zengchong Peng, Dong Lin, Anna A. Guliakova, Qun Zhang, Guodong Zhu
Summary: This study reports a dual-mode proximity sensor based on an oxide thin-film transistor(TFT) that utilizes a tungsten carrier suppresser to develop semiconducting materials and devices. The sensor performs well in flat panel display applications and can also sense the proximity and angle of approach of charged objects.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Cong Peng, Huixue Huang, Meng Xu, Longlong Chen, Xifeng Li, Jianhua Zhang
Summary: This paper proposes a facile modifying technique for self-aligned top-gate In-Ga-Zn-O (IGZO) thin-film transistors (TFTs) by controlling the process parameter of the passivation layer at relatively low temperatures. The modified IGZO TFTs show stable electrical performance.
Article
Chemistry, Multidisciplinary
Yu-Jin Hwang, Do-Kyung Kim, Sang-Hwa Jeon, Ziyuan Wang, Jaehoon Park, Sin-Hyung Lee, Jaewon Jang, In Man Kang, Jin-Hyuk Bae
Summary: By controlling the annealing time, the effect of structural relaxation on the electrical characteristics and bias stability of zinc-tin oxide thin-film transistors (TFTs) was investigated. Increased structural relaxation led to an increase in oxygen vacancies, resulting in higher mobility and a negative shift in threshold voltage. The positive-bias stress of the TFTs was enhanced with increased structural relaxation.
Article
Engineering, Electrical & Electronic
Yu-Shien Shiah, Kihyung Sim, Yuhao Shi, Katsumi Abet, Shigenori Ueda, Masato Sasase, Junghwan Kim, Hideo Hosono
Summary: This study successfully fabricated ultrastable thin-film transistors with mobilities of 70 cm(2) (V s)(-1) by understanding the origins of instability in high-mobility amorphous oxide transistors. The research identified the sensitivity of amorphous oxide semiconductors to externally introduced impurities and defects, and explained the mechanism of how carbon-monoxide-related impurities affect the stability of high-mobility indium tin zinc oxide transistors.
NATURE ELECTRONICS
(2021)
Article
Chemistry, Physical
Chan-Hwi Kim, Yu Jung Park, Jung Hwa Seo, Han-Ki Kim
Summary: This study investigates the characteristics of barium-addition indium-zinc-tin-oxide (B-IZTO) channels and their applications in thin film transistors (TFTs) and light emitting transistors (LETs). The addition of barium effectively suppresses oxygen vacancies in the channels, leading to improved stability in TFTs and enhanced performance in LETs.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
Jidong Jin, Xiaoyu Lin, Jiawei Zhang, Jeongho Lee, Zhenyuan Xiao, Soobin Lee, Jaekyun Kim
Summary: Low-voltage indium-tin-zinc-oxide (ITZO) thin-film transistors (TFTs) with excellent device performance and bias stability are developed using a dual-channel layer and an anodic-oxide gate dielectric layer. The dual-channel structure enhances device performance and bias stability compared to the single-channel structure. The ITZO TFTs gated with anodic AlxOy exhibit low-voltage operation, high mobility, and good operational stability, making them suitable for low-power, portable, and wearable electronics.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Wei Zhong, Liangyun Kang, Sunbin Deng, Lei Lu, Ruohe Yao, Linfeng Lan, Hoi Sing Kwok, Rongsheng Chen
Summary: The study found that ITZO thin-film transistors with a scandium oxide (Sc2O3) passivation layer showed excellent electrical performance and stability, especially under negative bias temperature stress and positive bias temperature stress. In contrast, devices with an aluminum oxide (Al2O3) passivation layer exhibited poorer stability.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Physics, Applied
Subhash Singh, Hiroyuki Matsui, Shizuo Tokito
Summary: In this study, printed single and dual-gate organic thin film transistors (OTFTs) and p-channel metal-oxide-semiconductor (PMOS) inverters fabricated on flexible polyethylene naphthalate substrate were reported. Inkjet printing was used for all electrodes, while the parylene dielectric was formed by chemical vapor deposition. The research demonstrated the performance advantages of dual-gate OTFTs and the characteristics of PMOS inverters.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Han-Lin Zhao, Fei Shan, Xiao-Lin Wang, Gergely Tarsoly, Jae-Yun Lee, Sung-Jin Kim
Summary: In this study, low operating voltage metal oxide transistors were achieved for wearable electronics by depositing a tungsten-doped indium oxide semiconductor on top of an aluminum oxide dielectric. By optimizing the tungsten content, the transistor showed improved charge carrier mobility, higher ON/OFF current ratio, and reduced subthreshold swing. The bias stability of the device was also significantly improved, possibly due to the suppression of oxygen vacancies by the doping.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Nanoscience & Nanotechnology
Heidi A. Schwartz, Hannah Laurenzen, Asma Marzouk, Manuel Runkel, Kai Oliver Brinkmann, Detlef Rogalla, Thomas Riedl, Sahel Ashhab, Selina Olthof
Summary: The band gap of CsPbxSn1-xBrx thin films can be tuned between 1.86 eV and 2.37 eV and the variation is nonlinear with the Pb/Sn ratio. A slight band gap narrowing is found for low Pb content. Valence band varies with the Pb/Sn ratio, while the conduction band is barely affected.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Andre Mayer, Neda Pourdavoud, Zineb Doukkali, Kai Brinkmann, Johannes Rond, Johannes Staabs, Ann-Christin Swertz, Frederic van gen Hassend, Patrick Goerrn, Thomas Riedl, Hella-Christin Scheer
Summary: This study aims to improve methylammonium lead bromide layers using thermal imprinting technique, resulting in larger grain size and reduced side-product content. Experimental results show that post-processing can achieve high-quality perovskite layers with large grains, which is crucial for device manufacturing.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Andre Mayer, Tobias Haeger, Manuel Runkel, Johannes Rond, Johannes Staabs, Frederic van Gen Hassend, Arne Roettger, Patrick Goerrn, Thomas Riedl, Hella-Christin Scheer
Summary: The quality and stability of devices made from polycrystalline layers of organic-inorganic perovskites depend on grain sizes. Thermal imprint as a post-processing step can induce grain growth and provide a flat surface. In MAPbBr(3) layers, imprinting at temperatures above 120°C is recommended for grain growth, with temperature being the main parameter affecting the process.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Energy & Fuels
Kai Oliver Brinkmann, Tim Becker, Florian Zimmermann, Cedric Kreusel, Tobias Gahlmann, Tobias Haeger, Thomas Riedl
Summary: This paper analyzes and explains the root cause of the high EQE values, finding that the high refractive index of the perovskite absorber and the optical properties of the transparent electrode strongly affect the transmittance of light and the spectral position of the peak.
Article
Materials Science, Multidisciplinary
Leonie Gomell, Tobias Haeger, Moritz Roscher, Hanna Bishara, Ralf Heiderhoff, Thomas Riedl, Christina Scheu, Baptiste Gault
Summary: The microstructure of a material plays an important role in its thermoelectric performance. In this study, the researchers investigated the microstructure and local properties of the Heusler-Fe2VAl compound using advanced microscopy techniques. They found that laser surface remelting can be used to manipulate the microstructure, leading to improved thermoelectric performance at room temperature.
Article
Nanoscience & Nanotechnology
Lukas Schmidt-Mende, Vladimir Dyakonov, Selina Olthof, Feray uenlue, Khan Moritz Trong Le, Sanjay Mathur, Andrei D. Karabanov, Doru C. Lupascu, Laura M. Herz, Alexander Hinderhofer, Frank Schreiber, Alexey Chernikov, David A. Egger, Oleksandra Shargaieva, Caterina Cocchi, Eva Unger, Michael Saliba, Mahdi Malekshahi Byranvand, Martin Kroll, Frederik Nehm, Karl Leo, Alex Redinger, Julian Hoecker, Thomas Kirchartz, Jonathan Warby, Emilio Gutierrez-Partida, Dieter Neher, Martin Stolterfoht, Uli Wuerfel, Moritz Unmuessig, Jan Herterich, Clemens Baretzky, John Mohanraj, Mukundan Thelakkat, Clement Maheu, Wolfram Jaegermann, Thomas Mayer, Janek Rieger, Thomas Fauster, Daniel Niesner, Fengjiu Yang, Steve Albrecht, Thomas Riedl, Azhar Fakharuddin, Maria Vasilopoulou, Yana Vaynzof, Davide Moia, Joachim Maier, Marius Franckevicius, Vidmantas Gulbinas, Ross A. Kerner, Lianfeng Zhao, Barry P. Rand, Nadja Glueck, Thomas Bein, Fabio Matteocci, Luigi Angelo Castriotta, Aldo Di Carlo, Matthias Scheffler, Claudia Draxl
Summary: Metal halide perovskites are a new type of solution processed semiconductors that can compete with traditional semiconductors in functionality, especially in optoelectronic devices. Despite breakthroughs, challenges remain in terms of stability, reproducibility, and toxicity.
Article
Materials Science, Multidisciplinary
A. Mayer, T. Haeger, M. Runkel, J. Staabs, J. Rond, F. van Gen Hassend, P. Goerrn, T. Riedl, H-C Scheer
Summary: Promising new materials like solution-processable perovskites may provide devices with superior properties. This study focuses on the organic-inorganic perovskite methylammonium lead bromide (MAPbBr(3)) and investigates its imprinting process. The results show that starting with a large-grained layer is optimal for replicating micro/nano-structures. Analogies with thermoplastic polymers are used to understand the shaping process of polycrystalline perovskites, and it is discovered that grain size and shape can be controlled by the imprinted pattern.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Ivan Shutsko, Maximilian Buchmueller, Maik Meudt, Patrick Goerrn
Summary: Optical metasurfaces offer precise control of light properties at the nanoscale and can be implemented using a solution-based growth method with silver nanoparticles. This approach allows for direct application in optical systems without the need for post-processing.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Ivan Shutsko, Maximilian Buchmueller, Maik Meudt, Patrick Goerrn
Summary: Disordered hyperuniformity (DHU) is a significant manifestation of engineered disorder aiming to overcome limitations related to order. A novel and facile method for the fabrication of DHU metasurfaces is proposed, which allows for in-situ control of the k-space by illuminating the growing metasurface with light. The experimental confirmation of anisotropic stealthy DHU is achieved through light-controlled growth.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Editorial Material
Nanoscience & Nanotechnology
Peter Muller-Buschbaum, Thomas Riedl
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Tim Hasselmann, Bujamin Misimi, Nils Boysen, David Zanders, Jan-Lucas Wree, Detlef Rogalla, Tobias Haeger, Florian Zimmermann, Kai Oliver Brinkmann, Sebastian Schaedler, Detlef Theirich, Ralf Heiderhoff, Anjana Devi, Thomas Riedl
Summary: In this study, highly conductive silver films were successfully grown at low temperatures using plasma-enhanced spatial ALD with a newly introduced nitrogen-based silver precursor. These silver films, used as bottom electrodes in organic solar cells, showed comparable performance to those made by traditional high-temperature vacuum processes.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Chemistry, Physical
Jarla Thiesbrummel, Francisco Pena-Camargo, Kai Oliver Brinkmann, Emilio Gutierrez-Partida, Fengjiu Yang, Jonathan Warby, Steve Albrecht, Dieter Neher, Thomas Riedl, Henry J. Snaith, Martin Stolterfoht, Felix Lang
Summary: Understanding the performance losses in all-perovskite tandem photovoltaics is crucial for advancing toward commercialization. This study characterizes the individual sub-cells in all-perovskite tandem stacks and shows that non-radiative losses dominate the overall recombination. Through various approaches, the open-circuit voltage of the high-gap perovskite subcell is enhanced, leading to improved efficiency in all-perovskite tandem solar cells.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Charles Otieno Ogolla, Yannik Loth, Tobias Haeger, Cedric Kreusel, Manuel Runkel, Thomas Riedl, Benjamin Butz, Anna Katharina Wigger, Stephan Schaeffer, Peter Haring Bolivar
Summary: In this study, THz-sSNOM was used for nanoscale imaging of CsPbBr3 thin films, and the local THz nanoscale conductivity was derived using a scattering model. The analysis of the obtained signals confirmed the presence of halide vacancies (VBr) and Pb-Pb bonds at the CsPbBr3 grain boundaries, which resulted in charge carrier trapping and nonradiative recombination. This study establishes THz-sSNOM as a powerful analysis platform for thin-film semiconductors like LHPs.
Article
Computer Science, Information Systems
Utpal Kalita, Christian Tueckmantel, Thomas Riedl, Ullrich R. Pfeiffer
Summary: This paper presents a multi-finger doubler based on amorphous-indium gallium zinc oxide (a-IGZO) thin film transistors (TFT) operating at GHz frequency. The doubler and the TFTs have been fabricated in-house with chromium (Cr) gate electrodes. The device output power, the threshold voltage mismatch, and breakdown characteristics are explained with the help of the model. The peak second harmonic conversion gain of the doubler is measured to be -32 dB at a gate overdrive voltage of around 2.8 V for a 500 MHz input signal. This second harmonic output frequency exceeds the TFT's transit and maximum oscillation frequencies.