EECS Colloquium

                                                                                                                        Host: Young Min Song / Language: English

Friday, March. 28, 2025, 14:30~

Haerim Hall, EECS-B Bldg. 1st Floor

 Development of high-performance p-type transistors

Prof. Yong-Young Noh

Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH)

 
[Abstract]                                                                                                                                                                                                                                                                                                                                                                                                                                      

Developing high-mobility p-type oxide semiconductors that can be grown using silicon-compatible processes at low temperatures, has remained challenging in the electronics community to integrate complementary electronics with the well-developed n-type counterparts. This presentation will discuss our recent progress in developing high-performance p-type semiconductors as channel materials for thin film transistors. For the first part of my talk, I present an amorphous p-type oxide semiconductor composed of selenium-alloyed tellurium in a tellurium sub-oxide matrix, demonstrating its utility in high-performance, stable p-channel TFTs, and complementary circuits [1]. Theoretical analysis unveils a delocalized valence band from tellurium 5p bands with shallow acceptor states, enabling excess hole doping and transport. Selenium alloying suppresses hole concentrations and facilitates the p orbital connectivity, realizing high-performance p-channel TFTs with an average field-effect hole mobility of ~15 cm2 V-1 s -1 and on/off current ratios of 106 ~107 , along with wafer-scale uniformity and long-term stabilities under bias stress and ambient aging. Tin (Sn2 ) halide perovskites emerge as promising p-type candidates but suffer from low crystallisation controllability and high film defect density, which result in uncompetitive device performance. In the second part of my talk, I would like to introduce a general overview and recent progress of our group of p-type Sn-based metal halide perovskites for applying field-effect transistors (FETs). I will mainly address inorganic perovskite thin-film transistors with exceptional performance using high-crystallinity and uniform cesium-tin-triiodide-based semiconducting layers with moderate hole concentrations and superior Hall mobilities, which are enabled by the judicious engineering of film composition and crystallization. The optimized devices exhibit high field-effect hole mobilities of over 50 cm2 V−1 s −1 , large current modulation greater than 108 , and high operational stability and reproducibility [1,2]. Next, I will introduce A-site cation engineering method to achieve high-performance pure-Sn perovskite thin-film transistors (TFTs). We explore triple A-cations of caesium-formamidinium-phenethylammonium to create high-quality cascaded Sn perovskite channel films, especially with low-defect phase-pure perovskite/dielectric interface. As such, the optimized TFTs show record hole mobilities of over 70 cm2 V−1 s −1 and on/off current ratios of over 108 , comparable to the commercial low-temperature polysilicon technique level [3]. The p-channel perovskite TFTs also show high processability and compatibility with the n-type metal oxides, enabling the integration of high-gain complementary inverters and rail-to-rail logic gates.

References

[1] A. Liu, Y.-Y. Noh et al, Nature, 629, 798–802 (2024) 

[2] A. Liu, Y.-Y. Noh et al, Nature Electronics 5, 78-83 (2022). 

[3] A. Liu Y.-Y. Noh et al, Nature Electronics 6, 559-571 (2023). 

[4] H. H. Zhu, Y.-Y. Noh et al, Nature Electronics 6, 650-657 (2023). 

[Short Biography]

Selected Representative Publication 

• Selenium alloyed tellurium oxide for amorphous p-channel transistors, Ao Liu*, Yong-Sung Kim, Min Gyu Kim, Youjin Reo, Taoyu Zou, Taesu Choi, Sai Bai, Huihui Zhu*, Yong-Young Noh*, Nature, 629, pages798–802 (2024) 

• Tin perovskite transistors and complementary circuits based on A-site cation engineering, Huihui Zhu, Wonryeol Yang, Youjin Reo, Guanhaojie Zheng, Sai Bai, Ao Liu*, Yong‐Young Noh* Nature Electronics, 6(9), 650-657 (2023) 

• High-performance metal halide perovskite transistors, Ao Liu*, Huihui Zhu, Sai Bai, Youjin Reo, Mario Caironi, Annamaria Petrozza, Letian Dou, Yong-Young Noh*, Nature Electronics, 6(8), 559-571 (2023) 

• High-Performance Inorganic Metal Halide Perovskite Transistors, Ao Liu, Huihui Zhu, Sai Bai, Youjin Reo, Taoyu Zou, Myung-Gil Kim, Yong-Young Noh*, Nature Electronics 5(2), 78-83 (2022) 

• Neuromorphic computing based on halide perovskites, Maria Vasilopoulou*, Abd Rashid bin Mohd Yusoff, Yang Chai, Michael-Alexandros Kourtis, Toshinori Matsushima, Nicola Gasparini, Rose Du, Feng Gao, Mohammad Khaja Nazeeruddin, Thomas D Anthopoulos*, Yong-Young Noh*, Nature Electronics 6(12), 949-962 (2023) 

RESEARCH INTERESTS

• Emerging P-TYPE semiconductors (Halide perovskite, Metal oxide, Metal chalcogenide, and 2D Layered materials for Thin-Film Transistors applications 

• Emerging P-TYPE semiconductors for LEDs applications 

EDUCATION

GIST, Gwangju, Korea Ph.D, Materials Sci. & Eng. 2005

GIST, Gwangju, Korea MS Materials Sci. & Eng. 2002

Dongguk University, Seoul, Korea BS Chemical Engineering 2000