Professor Ung Choi from the School of Advanced Materials Engineering at Kookmin University, and the joint research teams of Kyung Hee University and the University of Waterloo in Canada developed a highly-sensitive phototransistor using MoS2. This is known as the next generation graphene. This accomplishment was published on the cover page of the latest issue (April 1, 2015) of “Advanced Materials,” a prestigious journal in the new materials field published in Germany.
The paper entitled “Giant Photoamplification in Indirect-Bandgap Multilayer MoS2 Phototransistors with Local Bottom-Gate Structures” proved the giant photo amplification effect of the multilayer MsS2 transistor with local bottom-gate structure. The results of the study showed that it is highly possible to use MoS2 in various applications such as transparent and bendable touch screen panel, photovoltaic cell, and image sensor for the digital camera.
MoS2 is a semiconductor material with two-dimensional crystal structure similar to graphene. Due to its superior transistor characteristics, it is highly recognized as the next generation grapheme. The transistor using the single-layer MoS2 has excellent characteristics but developing products from it is difficult due to complex manufacturing processes.
To overcome this limitation, the joint research team studied its characteristics further and produced the transistor using multilayer MoS2 that can be manufactured using simple processes. Their study results were published in various prestigious journals such as Nature Communications, Advanced Materials, and Nano Research.
Through this paper, Professor Ung Choi reported a giant photo amplification effect for the first time and it increased the possibility of manufacturing MoS2 transistor products. Experiments and computations proved that giant photo amplification characteristics similar to the conventional single layer MoS2 can be replicated at the multilayer MoS2 phototransistor with local bottom-gate structure.
This study result suggested that a multilayer MoS2 transistor’s limitation regarding decline in photoelectric characteristics can be overcome through transistor structure change. It also proposed a higher possibility of applying the multilayer MoS2 transistor in other various areas including replacement of silicone photoelectric element.
Joint corresponding authors for this paper are Professor Ung Choi from the School of Advanced Materials Engineering at Kookmin University, Professor Seon-Guk Kim from the Department of Electronics and Radio Engineering at Kyung Hee University, and Professor Youngki Yoon from the Department of Electrical and Computer Engineering at University of Waterloo. This study was supported by National Research Foundation of Korea, Korea Evaluation Institute of Industrial Technology and Natural Sciences, and Engineering Research Council of Canada.
The “Advanced Materials” is a weekly academic journal published by Germany’s Wiley-VCH, and it is one of the most prestigious journals in the new material field (citation index 15.409). Through strict screening processes, only important scientific achievements are published here. Many research results published in this journal have been reported by media organizations.