Choi Wonjun, Ahn Jongtae, Kim Ki-Tae, Jin Hye-Jin, Hong Sungjae, Hwang Do Kyung, Im Seongil
Van der Waals Materials Research Center, Department of Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
Center of Opto-Electronic Materials and Devices, Post-Silicon Semiconductor Institute, Korea Institute of Science and Technology (KIST), 85, Hoegi-ro, Dongdaemun-gu, Seoul, 02792, Republic of Korea.
Adv Mater. 2021 Sep;33(38):e2103079. doi: 10.1002/adma.202103079. Epub 2021 Aug 2.
Highly crystalline 2D/3D-mixed p-transition metal dichalcogenide (TMD)/n-Ga O heterojunction devices are fabricated by mechanical exfoliation of each p- and n-type material. N-type β-Ga O and p-type TMD separately play as a channel for junction field effect transistors (JFETs) with each type of carriers as well as materials for a heterojunction PN diode. The work thus mainly focuses on such ambipolar channel transistors with two different types of channel in a single device architecture. For more extended applications, the transparency of high energy band gap β-Ga O (E ≈ 4.8 eV) is taken advantage of, firstly to measure the electrical energy gap of p-TMDs receiving visible or near infrared (NIR) photons through the β-Ga O . Next, the p-TMD/n-Ga O JFETs are put to high speed photo-sensing which is achieved from the p-TMD channel under reverse bias voltages on n-Ga O . The photo-switching cutoff frequency appears to be ≈16 and 29 kHz for visible red and NIR illuminations, respectively, on the basis of -3 dB photoelectric power loss. Such a high switching speed of the JFET is attributed to the fast transport of photo-carriers in TMD channels. The 2D/3D-mixed ambipolar channel JFETs and their photo-sensing applications are regarded novel, promising, and practically easy to achieve.
通过对每种p型和n型材料进行机械剥离，制备出了高度结晶的二维/三维混合p型过渡金属二硫属化物（TMD）/n-Ga₂O₃异质结器件。n型β-Ga₂O₃和p型TMD分别作为具有每种载流子类型的结场效应晶体管（JFET）的沟道以及异质结PN二极管的材料。因此，这项工作主要集中在单个器件架构中具有两种不同类型沟道的双极型沟道晶体管上。为了实现更广泛的应用，利用了高带隙β-Ga₂O₃（E₉₀≈4.8 eV）的透明度，首先通过β-Ga₂O₃测量接收可见或近红外（NIR）光子的p-TMD的电能隙。接下来，将p-TMD/n-Ga₂O₃ JFET用于高速光电传感，这是在n-Ga₂O₃上的反向偏置电压下由p-TMD沟道实现的。基于-3 dB光电功率损耗，对于可见红光和近红外照明，光开关截止频率分别约为16 kHz和29 kHz。JFET如此高的开关速度归因于TMD沟道中光载流子的快速传输。二维/三维混合双极型沟道JFET及其光电传感应用被认为是新颖、有前景且实际易于实现的。
